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AsusWRT Firmware vs. AsusWRT-Merlin, Explained: Everything Behind the Routers’ Wi-Fi “Magic”

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If you’ve never heard of the AsusWRT-Merlin firmware, know that extra magic can be available to a select group of Asus routers. Extra from what, though, you might ask? From the stock firmware, called AsusWRT.

However, things are not as simple as one is better than the other, which is especially true considering the latest AsusWRT 5.0.

This post will inform you about the software that powers Asus home (Wi-Fi) routers and which one to use to, when applicable, sprinkle some magic on your beloved networking device.

It’s important to note, though, that manually installing (third-party) firmware on a router can be tricky and could render your router a paperweight when not done right. Consider yourself warned! If something happens, you’re on your own.

The general rule of tinkering is that if you want to venture outside the general tech norm, out of boredom or otherwise, tread lightly! With that out of the way, let’s start with what “firmware” is.

Dong’s note: I first published this piece on October 21, 2020, and updated it on May 19, 2024, to add relevant and up-to-date information.

The Asus RT-BE96U in actionThe Asus RT-AX57 Go being tested
The RT-BE96U and RT-AX57 Go are the two first Asus routers to get the AsusWRT 5.0 treatment.

What is firmware?

Firmware is like a mini operating system. Every tech gadget or electronics has to run on a piece of software. So, firmware for a router is like Windows for a computer. It decides how (well) the router functions and dictates what you can do with it.

However, firmware can be very different from an operating system.

Firmware vs. operating system

Both firmware and operating systems are software that manipulates the hardware to deliver specific results. But they differ in nuances.

Specifically, the firmware has low-level—more direct and crude—access to the hardware. It’s geeky and closely related to a device’s physical components.

On the other hand, an operating system has higher, safer, and more refined access to the hardware. It’s user-friendly and about giving users what they want instead of dealing with hardware components’ essential functions.

A crude analogy

Firmware is like the wiring and switches under the hood of a car, while the operating system consists of the control element inside the cabin, such as the driving wheel, shiny buttons, stalks, knobs, touchscreens, and whatnot. Most drivers only care about the latter and have no interest in the former, which, among other things, will make their hands dirty.

On a computer, the motherboard itself uses firmware called BIOS, which decides what kind of computer it is and which operating system—Windows, Linux, or macOS, for example—you can install on it and how.

Sometimes, the line between firmware and an operating system is blurred, and the two can be interchangeably used. For example, the firmware of Synology routers is so advanced that folks call them operating systems.

However, devices with limited functions, like the Internet of Things (IoT) gadgets, generally use firmware. Advanced devices, such as smartphones, tablets, or computers, use an operating system (on top of a firmware layer).

So, Wi-Fi routers mainly use firmware, but it’s also acceptable to call that an operating system.

Stock firmware

By default, the networking vendor ships their routers with installed firmware, often referred to as “stock firmware,” which can’t be changed. You may be able to upgrade the firmware to a newer/better version occasionally, but for the most part, the router’s features remain the same for the rest of its life.

Asus’s stock firmware, AsusWRT, is used in all home routers released in the past decade and the foreseeable future. (WRT stands for Wireless Receiver / Transmitter, a common acronym for Wi-Fi broadcasters.)

It’s worth noting that AsusWRT is one of the most robust firmware for Wi-Fi routers. Asus builds it using Linux via the GNU Project, with source code available to the public under GNU’s General Public License (GPL). That opens it up to third-party builds, including Merlin.

We’ll get to AsusWRT-Merlin momentarily, but first, let’s take a deeper dive into AsusWRT itself.

Dissecting the formidable AsusWRT

Below is the web user interface of the GT-AX6000 gaming Wi-Fi 6 router running the stock AsusWRT firmware. Asus’s gaming line-up generally has a red theme, while the RT series has less flashy colors.

Asus has a vast collection of Wi-Fi hardware options available in the following series:

  • The RT series: General consumer-grade standalone routers ranging from entry-level, mid-range, and high-end models. Improved variants might carry the “Pro” suffix, such as the RT-AX88U Pro. Some models include gaming-related features, such as the RT-AX82U. Most feature AiMesh as an option.
  • The TUF and ROG series: Gaming-related Wi-Fi routers of different tiers, including the highest-end flagship routers. Improved variants, such as the GT-AX11000 Pro, might carry the “Pro” suffix.
  • The ZenWiFi series: This series includes consumer-grade purpose-built AiMesh-based Wi-Fi systems with a broad range of configurations. Some variants have built-in MOCA or Powerline support.
  • The ExpertWiFi series: Hardware for networking enthusiasts and office environments. These are AiMesh-enabled business-oriented solutions with more advanced options in network customization and hardware design, available as purpose-built mesh systems, single (Wi-Fi) routers, APs, and switches.

Generally, all AiMesh-enabled hardware—most, if not all, Asus Wi-Fi 6 or newer routers—can work together to form a system.

Asus GT-AX6000 Multi Gig Wired AiMesh Setup with an RT-AX89X Note
Here’s the web interface of an Asus GT-AX6000 running AsusWRT stock firmware hosting an AiMesh system with the RT-AX89X as the satellite.

Regardless of the themes and their decoration, routers sharing the AsusWRT firmware share the same core feature set, which is among the most comprehensive among home routers. If you’re interested in what this firmware can do, I detailed that in this primer post on Asus routers.

Here, let’s focus on the firmware itself.

AsusWRT has so far gone through five major versions, including:

  • AsusWRT 1.0: Available in pre-Wi-Fi 4 routers. It’s the initial Asuswrt firmware with the kernel.
  • AsusWRT 2.0: Available with Wi-Fi 4 hardware and added support for USB storage.
  • AsusWRT 3.0: Available in Wi-Fi 5 and Wi-Fi 6 hardware and added the support for AiMesh starting with version
  • AsusWRT 4.0: This version is available primarily in Wi-Fi 6 and 6E hardware, starting with version It added multiple levels of gaming and security. It’s the last version with the kernel.
  • AsusWRT 5.0: This version was first available in late 2023 in Asus’s latest hardware, such as the new ExpertWiFi family and Wi-Fi 7 hardware. It uses the new kernel. Among other improvements, it supports self-defined networks, advanced VPN, Gaming networks, and more.

The self-defined network (SDN) feature in AsusWRT 5.0 allows users to create multiple virtual SSIDs that fit different scenarios, such as office splace, Guest Wi-Fi, IoT, etc. This feature has different names:

  • SDN in Asus’s new ExptertWiFi business hardware.
  • Guest Network Pro in its ROG gaming and high-end RT models.
  • Smart Home Master in the Wi-Fi 7 ZenWiFi lineup.

Understanding a firmware version

Asus regularly releases firmware updates for its routers, which is generally a good thing. Many of these updates add new features to the hardware—they do more than patch security vulnerabilities. However, some updates may inadvertently cause a particular model to go haywire, likely because the company tries to do so much with its routers. That’s often the case with a major upgrade.

All AsusWRT firmware releases, the version number of which generally appears at the top of a router’s web user interface, share the same format. Let’s zoom in on one to find out what it means.

Note: An AsusWRT firmware version that starts with 9.x.x.x instead of 3.x.x.x is a beta release meant for testing purposes only.

Asuswrt firmware
An AsusWRT firmware version includes three parts marked here with the hovering red, orange, and yellow lines.

There are three parts in a particular firmware release, such as shown above:

  • The first four digits (, as shown with the hovering red line): The Linux kernel version—the super-major release, often referred to as a “branch”. It’s the base of the firmware and tends to remain for years (often a decade or more) without changing. Generally, when it’s changed, it conveys the most significant change in the firmware itself. The kernel has been there since Asus’s Wi-Fi 4 routers, such as the 2011 RT-N66U, and didn’t change until the release of the company’s first Wi-Fi 7 hardware in late 2023.
  • The three middle digits (386, orange): Signify major updates by Asus that include significant changes or added features. This generally changes every one or a couple of years.
  • The last digit after an underscore (47629, yellow): This is the minor release, which is often used to stabilize the major update or improve security. It changes the most frequently.

Generally, Asus allows firmware upgrades and downgrades on its hardware. In the latter case, you can only install firmware that is as old as the particular hardware’s initial release.

Tips on AsusWRT kernel

Considering the vast number of hardware options, most of which can be combined into a mesh system using the AiMesh feature, firmware can be tricky for Asus, especially with hardware running firmware versions that start with the kernel.

AiMesh was first added as a major feature via firmware version 384 in early 2018—represented by the RT-AC86U. It was buggy at first, but it became stable with the latest minor updates. In early 2020, Asus released version 386, which was also buggy in the early stages, to add AiMesh 2.0 via the introduction of the ZenWifi product line. By late 2022, version 386 had become fully mature, and Asus released version 388 (dubbed Asuswrt 4.0) to add better VPN support, triple gaming/protection levels, and more. This version became stable by late 2023.

When it comes to updating—especially in an AiMesh setup of mixed hardware units using wireless backhauling—keep the following three items in mind:

  1. Avoid the initial major release: This is the first firmware version of a model where the middle three digits of the firmware version change, such as from 384 to 386 or from 386 to 388. Generally, things start to be good with the first minor update to a major firmware release.
  2. Avoid using Auto-Update for firmware: Instead of letting the hardware update itself, you should update the firmware when you see fit. (It’s OK to choose Auto-Update for the security-only updates when that’s an option.)
  3. Version consistency (in a mesh system): Generally, it would be best to use the firmware version of the same major release for all AiMesh members. (Mixing hardware of different major releases can produce mixed results.)

On the one hand, moving between major releases might break your AiMesh setup or even your standalone router. On the other hand, new hardware comes with a specific initial version that is out of the box—you have no option to downgrade it—and some old models won’t get the latest release. So, depending on the mesh combo, your luck will vary.

As a rule, when using hardware with the kernel in a mesh system, it’s best to wait for a few minor updates of a major release before upgrading. Depending on the hardware combo, you might need to rebuild the system from scratch or reset and re-add a satellite node if you change the major firmware version (in one or all hardware units involved.)

Asus Firmware Guest Network ProAsus Firmware Guest Network
AsusWRT vs. AsusWRT kernels: The former (left) has many more features, including a robust Guest Network Pro that offers multiple virtual SSIDs available at the router or the entire AiMesh system. The old version only allows for one SSID per band available systemwide.

The new kernel (AsusWRT 5.0)

In late 2023, Asus made available its first Wi-Fi 7 router, the RT-BE96U. Together with it, there’s a new super-major firmware build running kernel version, currently with the 102 major release. It’s AsusWRT 5.0 to replace its current AsusWRT 4.0, which is the 388 release of its kernel, as mentioned above.

Subsequently, this kernel is also used for the GT-BE98 Pro and the new ExpertWifi family. It’s safe to say all new Asus networking hardware released in 2024 and later, regardless of the Wi-Fi standards or performance grades, will use the kernel. (The newly released RT-AX57 Go travel router has it.)

During 2023, this firmware was available as a beta for some existing hardware originally released with the branch—including RT-AX86U Pro, RT-AX88U Pro, GT-AX11000 Pro, GT-AXE16000, GT-AX6000, ZenWiFi Pro ET12/XT12—which will likely be the ones to get the official version of AsusWRT 5.0 down the line.

The firmware is relatively new, so it’s hard to tell. However, so far, it was buggy in 2023. In early 2024, when it was available with official hardware, it proved to be much more stable and provided more refined support for AiMesh. Specifically, mixing hardware of different Wi-Fi standards and firmware versions seems to work better—within the extent of common hardware features and Wi-Fi performance grades.

Additionally, the new firmware has better support for VPN, Parental Controls, and Network Protection, as well as Guest Network Pro, which allows for self-defined networks (SDNs). Depending on the hardware segment, users can create between three and five additional virtual SSIDs to use at the route or the entire mesh system to better segment or manage their home network.

Additionally, the new version continues the universal backup/restore, meaning you can backup the settings of an old Asus router to a file and restore them to a new one. This works on almost all Asus routers with very few exceptions.

It’s safe to say that kernel-based AsusWRT will continue to be improved via major and minor releases in the near future as more hardware supporting it becomes available.

Asus RT-AX88U Pro Wi-Fi 6 RouterThe Asus GT-AX11000 Pro has eight external antennas that only open about 30 degrees outward, but you can swivel them around 360 degrees.
The GT-AX1100 Pro and RT-AX88U Pro are the two latest Asus routers that have the Merlin firmware treatment.

For now, this version is still in its early stages, and while all of its builds are available as open source, no third-party firmware creator has yet adopted them. That brings us to AsusWRT-Merlin.

AsusWRT-Merlin: Special third-party firmware for select Asus routers

Some networking vendors allow users to put third-party firmware on their hardware. Popular open-source router firmware like DD-WRT can work on (select) routers from multiple networking vendors. They tend to be completely different from the stock firmware and, therefore, quite hard to handle.

On the other hand, Merlin is the third-party firmware available only to certain Asus routers. Its official name is AsusWRT-Merlin, though some might call it MerlinWRT. You can also call it Merlin for short. Merlin itself is open-source software.

The Merlin group, led by Eric Sauvagea, alters the AsusWRT source code based on the open-source license to create a (better) alternative and make it available for free. In other words, Merlin is based on the stock firmware and, therefore, always becomes available, if at all, (long) after a router’s release.

Generally, AsusWRT-Merlin has all the settings and features of Asuswrt and then some more. In other words, it encompasses the stock firmware as an enhanced version of the same major build. That’s been the case with the kernel, currently at 388 release. For now, there’s no word yet on when or if the kernel will be ported to Merlin.

So similar to the stock in functions and interface, Merlin is as easy (or hard, depending on who you ask) to use as AsusWRT. If you know one, you can handle the other. And that’s a good thing.

The list of Asus routers that can run Merlin

Here is the list of current Asus routers that you can put Merlin on at publication time—there’s no Wi-Fi 7 router yet. Follow the links to read their reviews.

Some old routers, including the RT-N16, RT-N66U, RT-AC66U, RT-AC56U, RT-AC87U, and RT-AC3200, are no longer supported and will not receive Merlin firmware updates.

While not all Asus routers get the Merlin treatment, most of those featuring Wi-Fi 6 and 6E do, and there might be even more in the future. In my experience, Merlin has worked exceptionally well on supported hardware.

Merlin firmware’s features

Asus GT-AX16000 VPNAsus GT-AXE16000 AiMesh with Merlin Firmware Tor and VPN Director Support
With Merlin, the GT-AXE16000 has many more VPN options, including support for VPN Director (much better in my experience than AsusWRT’s Fusion) and TOR at the client level. Merlin has the option of using a regular theme on a gaming router, but its features remain unchanged.

Here’s the complete list of Merlin’s features, but the shortlist of benefits includes:

  • Better VPN support, which, among other things, can route specific clients via VPN or globally.
  • More flexible DNS—you can set the DNS server for individual clients or globally.
  • Built-in TOR support for privacy, with individual client control, can route specific clients via TOR or globally.
  • More frequent firmware updates, especially when it comes to addressing bugs.
  • Better stability.
  • Lots of control, feature, and automation options via user scripts and add-on packages.
  • The same AiMesh support (for the most part).
Notes on moving between AsusWRT stock firmware and Merlin

Generally, AsusWRT and AsusWRT-Merlin are very friendly toward each other. That means:

  • You can move a router between these two firmware options at any time. Specifically, you can flash a router from AsusWRT to Merlin, and its settings will remain the same. The other way around, though, only common settings between the two will remain.
  • You can restore a router using a settings backup file for either firmware. And, just like stock firmware, you can restore the settings of one router to another. Depending on the routers involved, some settings might not be carried over in this case.
  • The Asus Router mobile app (made by Asus) also works with a router running Merlin.
  • Overall, Merlin’s web interface looks and feels the same as Asus’s stock firmware. You might not even notice that you’re using Merlin.
  • The AiMesh feature is available in Merlin (starting with version 384), and you can use routers of either firmware together—with unexpected hiccups in certain combos.
Asus Multi Gig Wired Backhaul Mesh GT-AXE16000 and ZenWiFi ET8 ComboAsus GT-AXE16000 AiMesh with ZenWiFi Pro ET12 Merlin Firmware
AsusWRT firmware vs. AsusWRT-Merlin: Here’s the web interface of the same Asus GT-AXE16000 hosting an AiMesh system with two ZenWiFi Pro ET12 running AsusWRT (left) and AsusWRT-Merlin. The latter also has the option of using the red theme. Note the common 386 major release of the two. Merlin’s web interface doesn’t show the kernel version.
AsusWRT-Merlin firmware and AiMesh

Note that you generally want to use AiMesh with the same firmware (AsusWRT or Merlin). Mixing the two, understandably, might lead to unexpected issues. Also, AiMesh is developed by Asus, so AsusWRT is naturally better and more predictable.

But in my testing, I’ve used multiple combos where the router unit runs Merlin, the satellites are on AsusWRT, and things are generally fine.

The other way around tends to be hit or miss. Specifically, using an AsusWRT router unit to host a Merlin satellite is not a good idea. But again, your mileage will vary, and generally, it’s best to use Merlin consistently when possible.

The performance of a hybrid system proved to be as fast and reliable as when AsusWRT was used across the board.

Still, remember that mixing hardware of different versions, let alone variants, will likely result in unexpected issues. And nobody can test all possible scenarios.

Asus’s take on Merlin

Asus didn’t give me any opinion on AsusWRT-Merlin. Instead, it only said it provided AsusWRT’s code as an open source under GPL, as mentioned above. However, the company told me one crucial thing: Putting Merlin on Asus hardware will not affect its warranty. Specifically, a Z told me:

“[…] as long as the router does not break/fail during the firmware change process, we will still provide the warranty for the hardware. The 3rd party software is not tested by ASUS, so we do not provide the warranty for the 3rd party software.

In short, using Merlin is risk-free if you don’t mess up the firmware migration process or expect tech support from Asus. And that’s fair game.

Asus Dual band Wi-Fi routers
Only two of these Asus Dual-band Wi-Fi 6 routers can currently run AsusWRT-Merlin. Care to guess which ones?

And that brings us to how you can put Merlin on your supported router today. The process is the same as doing a manual firmware upgrade or downgrade.

How to manually flash firmware (AsusWRT or AsusWRT-Merlin) on an Asus router

Installing the AsusWRT-Merlin firmware on a router is the same as manually upgrading the hardware using AsusWRT stock firmware. It’s a process called “flashing.” And it’s easy enough.

All you have to do is download the firmware and load it on the router via its web user interface, just like the firmware update process of any standard router.

The following are detailed steps to manually flash a Merlin or stock firmware file on an Asus router. I used an RT-AC88U unit for the screenshots below, but you can apply these steps to flashing any other model using stock or Merlin. The process is always the same—pick the hardware and firmware of your choice.

1. Download the (Merlin) firmware for your router

Here’s the link to get AsusWRT-Merlin for all supported routers. You want to download the latest Release version, though you can also try the beta if it’s newer and you want to be adventurous.

If you want to use stock firmware from Asus, Google the router’s model plus “firmware,” and you’ll find the download page for the router from Asus’s website. This page generally includes multiple firmware versions, the latest plus a few previous releases, in case you want to downgrade.

The download file is a compressed folder in .zip format. You first need to open this file (double-click on it) and extract the firmware file. Generally, the file you want is named after the router’s model plus the version number.

If there are more than one firmware files, each has a feature, such as the ROG vs. RT theme colors, and you can use any. In any case, if unsure, you can try one file after another in the step 3 below—the system won’t accept a non-firmware file.

Merlin Firmware Extract
It’s easy to extract the firmware file from a ZIP folder. Note the router’s model number in the file name.

In my case, I dragged and dropped the file onto a folder called “Merlin” on my Windows computer’s desktop area. The point is you need to remember where you put this firmware file.

2. Log in to the router web interface

Log in to the Asus router’s web interface from a connected computer. You can do this by navigating a browser from a locally connected computer to its default IP address,, or www.asusrouter.com.

RT-AC88U Firmware Update
On an Asus router’s interface, you can quickly jump to the firmware upgrade section by clicking on the firmware version at the top of the web page.

You’ll be asked for the username (“admin” by default) and password you created when you first set up the router. Once logged in, go to:

Administration -> Firmware Update

Alternatively, you can click on the firmware version at the top of the interface’s webpage to jump to the update section. Now, you’re ready to perform the firmware migration in the next step.

3. Upload the (Merlin) firmware

Click on the Upload button (see screenshot below). A dialog will pop up for you to navigate to the location on the computer that holds the firmware file. In my case, it’s the “Merlin” folder on the desktop, as mentioned above.

RT-AC88U Firmware Upload
Navigate to the location of the Merlin file and choose to open it.

Select the (Merlin) firmware file, then click Open (or double-click on the file). The flash process will start immediately.

Note: This process will take a few minutes. During this time, make sure you leave the router and the web interface alone. Don’t unplug the router or the computer from the power!

RT-AC88U Firmware Progress
The upgrade/migration process will take a few minutes and needs to be left alone.

After that, the router will restart, and the webpage will return to the login page. Log in to the interface again, and, if you have used a Merlin firmware file, you’ll see the Merlin logo at the top left corner of the page. You’re almost there.

Finally, manually restart the router one more time by unplugging it from power for a few seconds, then plugging it back in. (You can probably skip this step, but in my experience, a manual restart is always helpful after a firmware change. So do it!)

And that’s it. Mission accomplished.

If you want to switch back to AsusWRT, repeat the steps above using the router’s stock firmware. Again, the settings will (largely) remain.

AsusWRT firmware vs. AsusWRT-Merlin: The takeaway

If you have an Asus router with firmware that can run Merlin, it doesn’t hurt to give AsusWRT-Merlin a try. Everyone can benefit from the better stability Merlin brings to an Asus router. Additionally, using Merlin will make the geek inside you happy, if there’s one.

I know many advanced users who only buy an Asus router after Merlin is available, and I don’t blame them. One thing is almost always the case: If you have a Merlin-supported Asus router that hasn’t worked as well as you’d like, putting the third-party firmware on it magically makes it better, and if so, sometimes by a lot. Try it. You can always move back to AsusWRT.

However, Merlin is not a must-use or an upgrade to AsusWRT. Generally, if you choose to use Merlin, you’re on your own in support since Asus won’t help if you get into trouble. Additionally, hardware featuring the latest kernel version of Asuswrt stock firmware, so far, seems to enjoy similar stability and more features than Merlin. And you won’t need to choose—not yet. For now, it’s unclear if there’ll be Asuswrt-Merlin for the new kernel.

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107 thoughts on “AsusWRT Firmware vs. AsusWRT-Merlin, Explained: Everything Behind the Routers’ Wi-Fi “Magic””

  1. Hi Dong!

    I am a very rookie user but am much less so because of you! I recently bought a 88u pro and for the most part it works really well. I have been experiencing random slow-downs and disconnects though that last anywhere from a couple of seconds to minutes. I kept all the settings on the router to factory, except for turning off Smart Connect so I could have dedicated 2.4 GHz and 5 ghz channels. At the advice of some forms, I also got WIFI explorer lite to find a channel that seemed less crowded but that did not seem to have a significant impact one way or another.

    Do you think installing Merlin would possibly help solve some of these gremlins or should I look towards something else?
    I also have screenshots of my wireless settings and Wifi Explorer results but I am more than willing to provide anything else.


    Modem: Arris SurfBoard S33 (no uncorrectables in status page)

    Router: Asus RT-AX88U Pro

    Internet: Comcast 1gb

    Cabling: CAT5e or above

    I appreciate all that you do in making all of this accessible!

  2. Hey Dong, after reading above article I now have Merlin on GT-AX11000 and RT-AX88U(mesh node). The mesh network seems stable now and I feel more comfortable in making changes.
    I am, however, now seeing the router temp and nervous about the 158 degree running temp. Is this normal operating temp for the 11000?

  3. Hi Dong – your posts are an amazing source of knowledge. Mixing the technical with human-readable is a rare skill.

    I have an XT12 2-node mesh (router and satellite), and I want to move to Merlin. What order should the upgrade be done; router first and then satellite, or the other way around?

  4. Hello Dong,
    Do you have any special preference or useful tips for Merlin to improve everyday usage for a regular home user?
    I wish everyone a great day!

    • Generally, that varies from one router to another and from one location to another, Alex. There’s no one-size-fits-all in Wi-Fi customization. My advice is always keep things at default and change them slowly, keep tabs on the changes and reverse them when necessary, etc. Tread lightly.

    • So one thing I’m confused about is Merlin support for the XT8 (RT-AX95Q). This doesn’t appear on the main Merlin support list you sent out, but does appear on a branch (something called GNUTON) which I admit I don’t totally understand.

      What is your take on this?

      Randy Frank

      • As mentioned, Asuswrt (and Merlin) are open-source software. As such, it can be modified by anyone. I’d not use firmware from an unknown source, though.

        • So in doing some more research on the Merlin Gnuton1 build thread (which is the only way to get Merlin for the XT8 at the moment), it does appear to be pretty well regarded. Evidently it pretty much takes the Merlin Asuswrt build and simply creates a version specific to the XT8 (and some other models which at the moment aren’t supported by the main Merlin thread) but really isn’t a separate development thread. So I took the plunge yesterday and upgraded my 3 node XT8 AIMesh config to the Merlin Gnuton1 version, and it all went without a hitch, and so far so good. At the moment it’s based on Merlin 386.07_2 but will shortly be upgraded to 386.08 (which has already been done for several other Asys routers which only the Gnuton1 build supports).

  5. Just in case you have the Asus TUF-5400, it works too with GNUton’s builds: https://github.com/gnuton/asuswrt-merlin.ng/issues/147#issuecomment-1079668398

    I love this model so much:

    1. Surprisingly cheap in Thailand: only $129 new! I don’t know why. I can’t get anything as good as this one under $150 here.

    2. I can make it support all 5GHz channels, just set country to Korea! Amazing!

    3. I can install Merlin GNUton’s build!

    What I don’t like, but not a big deal:

    1. PPPOE doesn’t work with my Fiber provider, but it’s fine since I use a Mikrotik_RB750G as my router to dial PPPOE. Other people with different providers in Thailand also report the same.

    • Interesting. I guess regulations are less restrictive and less enforced than in the US. Over here, a violation can mean the end of your business. Thanks for sharing, Fred.

  6. Thank you Dong,
    Nice clear instructions (Sent a note ref first ASUSWRT photo, hope you received it). I have finished stage one of hardwiring house, just the guest bedrooms when it gets cold/wet. I bought the XT8s in the end (still need some wifi), hope to buy XT12 as router during Black Friday … that’ll be this stone house and garage set I hope for a while.
    Nicely done,

  7. Hi Dong, thanks for the clear tutorial

    I have a AX-56U router and tried out to change Firmware to Merlin, as described in your post. All goes smoothly until the end of the process, but upon restart, the Firmware has not changed. it remains the old one that was there at the beginning.

    any hidden option / Tricks to make my router switch firmware ?

  8. Hi, have just updated my new RT-AX86U with Merlin latest firmware (all good). Need to know if future Merlin firmware updates have to be downloaded and the update performed manually ie checking the website every so often, or by setting the auto update setting to on? I am not sure if this setting will point to Asus or Merlin update site? thanks

  9. Thanks for talking about third-party firmware, and giving some instruction about how to flash it. I’m using Merlin’s firmware (Eric’s) as we speak, on the RT-AX86U, and it’s performing admirably :-). Much better than the latest Asus firmware for the AX86U, which I also installed, tried for a few days, and found wanting.

    Very helpful to those that would like to try it, but are reluctant to take the risk. I can personally attest to the fact that the risks of flashing and using Merlin’s firmware are vanishingly small :-). And being a veteran of DD-WRT, OpenWRT, and Tomato, unbricking via serial console, etc., I can appreciate your helping users through this. Once you’ve done it, you realize how easy it all is.

    As to the comment about Merlin’s firmware “not fit for daily use”, I wonder if that person has ever used Asus fimware :-). I’ve reverted so many times that I’m wearing out the firmware image for version 42095 for my ZenWiFi :-). And version 46061 for the AX86U is also buggier than I can stand. My Tablo disconnects, and the data traffic statistics are not working right. On the other hand, the latest Merlin firmware for the AX86U is working really well…so there you go, different people, different experiences.

  10. thanx 10*6 Dong, at last someone who speaks plain English so at least a pc savvy person can understand. I had grown exasperated at the 99% rubbish on the web, conflicting confusing and contradictory mixing old tech with modern stuff and hugely puffed up only to find its sponsored by a VPN provider. eg Networks for dummies Wiley waste of space and patience.
    so you have saved my sanity
    After all – correct me – arent these networks basically same as a field wiring/cable routing diagram ie wiring starts from a marshalling cabinet in a control room (modem isp box – fibre – internet). Each cable has a number (IP address) goes to a field junction box labelled (home router user name passphrase SSID). The cable might have 64 cores each with a wire number (IP) going to a terminal strip with terminal numbers1-64. This is then cross wired to another terminal strip with 64 terminals but these fan out ( NAT) into local smaller cables 2,3 or 5 core all with wire numbers cable numbers going out to field instruments with ID tags
    I could draw this out as a block diag and it would be self evident, but in words makes you brain spin.
    I hope this makes sense and helps Network noobs
    I would be happy to produce the graphic of this if it can be posted here and you would kindly approve its accuracy first – to support your invaluable cause
    Robin (retired control systems engineer)

  11. Hi Dong,

    what is your opinion on Merlin wrt as compared to the new Asuswrt? it’s been a year since the post and as i’ve read, there was a big update from Asus a the beginning of 2021.

    is it still worth switching to Merlin?


      • thanks for the prompt reply,

        i asked the question because of the massive improvements (as i’ve read) of Asuswrt and not claiming that Merlin has fallen behind.

        • Merlin is not a must-have. You can skip it completely. It’s more of an option for geeks built on top of Asuswrt and not an independent development. That was true when I published the post, before that and continue to be that way… so your question was a bit irrelevant. But you’d already know that if you read the post in its entirety. The point is this website is where you should spend some time on the content… 🙂

  12. Hey Dong,

    Your words about Merlin and how it compares to Asus-WRT ring very true to me. I think this is an excellent article and I hope it turns a lot of people on to the goodness that is Merlin. Hopefully, some steady portion of them also consider donating to the project as something so good and free definitely deserves the support.

    That being said I am currently running stock firmware on my new GT-AX11000, but I’m only a week in and I am strongly considering going back to Merlin.

    Also, I took a cue from the comments and just donated $20 USD through the link on the Merlin page.

    Anyway, pardon me for reviving a year old comment thread and keep being awesome. Thanks.

  13. Dong,
    Thanks for the info in your blog regarding all the network,wifi stuff!
    Been reading for a while and have this question:
    I have the Asus ​RT-AC87U and have 1700 sqf home , two story home and there are few wifi drop outs in the signal. I do have xfinity internet 1 gb plan. My question was what asus wifi router with kind the same menu interface will be good to upgrade? on wifi 6? (Have Netgear cm1100 for internet modem).
    Thanks for your time!

  14. Hi Dong,

    I’ve got a stock Aimesh setup of 3 different routers 86u main + 68u and 66u_b1 as nodes. All working fine. I’ve bought an additional 68u from eBay (which was previously on Merlin but the seller flashed it back to stock before sending) to add to this but the main router refuses to see it. I’ve checked the firmware, reset the node, and made sure they are close together but nothing is making the main node find the new one.

    So a couple of questions:

    – is it possible that the new 68u has been “messed up” in someway (how do i check!) – I’ve got another 68u on its way from Amazon in order to check if that works or prove it’s the main node.
    – is there any chance flashing Merlin into the main node might help?

    • I can’t comment on stuff you bought from eBay, Steven. You need to check with the seller. And no, Merlin generally won’t improve AiMesh since it’s an Asus feature. On this front, Merlin is a step behind.

      • Thanks for the reply, I’m not after a comment on the “stuff I bought on ebay”, I was just asking whether you knew of any mods when switching to Merlin that might impact the ability of the master node to “see” a child. I read somewhere about Mac address being altered but can’t find it now!!!

          • I disagree. Merlin works fine with Asuswrt nodes and vice versa. There’s no technical reason why it should not, as the same AImesh coding is used all over. As for nodes not being reckognized, I would suggest factoryreset, followed by temporary cable bacbone (whilst doing setup).

  15. I enjoy reading your articles. Thanks. Just one question. After installing Merlin software, will “Network Protection powered by Trend Micro” will stay (or does it get removed)?

    • Yes, it’ll stay, Raj. Like I mentioned in the post, it generally has everything Asuswrt has in terms of features and settings, and then some.

  16. Hi Dong,
    You mention the ac88u has the most to offer with Merlin over the other Asus routers. What Merlin features would you say it has over the ac86u which I understand to have a faster CPU.

    • I didn’t say that, Chris. Also, it’s not just the hardware specs that matter, but also how mature the firmware is for the models.

      • Hi Dong,

        It was the line “In my experience, the RT-AC88U and RT-AX88U are currently the best Merlin options since they have the most to offer.” that made me think the ac88u had some special Merlin features not available to others. Firmware to hardware maturity makes sense thanks!

  17. It’s been about 4 years since I last used Merlin. I’m in the market for a new router to replace my 4 year old router that’s failing. Looking at picking up an Asus of some sort.
    Does the latest Merlin have the ability to connect to a IPSEC L2TP VPN server and to route traffic for certain subnets through that tunnel?

    • No ipsec l2tp vpn client on my 86u running merlin, i only saw ipsec l2tp as server. At lease openvpn speeds are very fast but not as fast as wireguard which is only available with ddwrt and openwrt supported routers.

  18. Many thanks for another great article. Now that Merlin does AiMesh 2.0 and I have 3 XT8s in service with the somewhat skittish current AsusWRT official firmware, I sure wish we could get some Merlin magic for that model! Any ideas whether that’s a possibility?

  19. Dear Dong

    I use my VPN Client a lot, I have an old Netgear Router, it has become slow and I constantly keep getting disconnected. So I want to buy an Asus Router and install Merlin on it to improve my overall connection quality, but mainly to have the VPN installed on it directly and active 24/7. My idea is to open two tunnels, one with VPN and one without VPN depending on the device that I use to connect with, to make it practical.

    I was thinking between the Asus RT-AC86U and the Asus RT-AC-88U. You have mentioned in your posts that you own and love the RT-AC88U because of it’s 8 ports, link aggregation, etc, but I was wondering if in my specific case where I need the VPN to work well, the better, newer processor of the RT-AC86U would make it a better option.

    Thanks so much for all the information you share with us, it is really very valuable.

    • OpenVPN is very CPU hungry. I would go with the faster CPU. I have been using the Asus RT-AC86U since May 2018, mainly for the VPN (as you want to), with Merlin Firmware.

      Hm, it was working well, but with the VPN on 24/7 it was freezing sometimes when the network traffic was high. Also, periodically I had to re-import the VPN settings file, because it didn’t connect anymore.

      I upgraded to the AX11000 in Jan 2021, as it had WiFi6 and had VPN Fusion, and has much stronger CPU.

      So far, it worked more or less well, but sometimes it stops giving the internet access. Everything else works, just no internet. I need to reboot it. I suspect it is because of the VPN.

      {Suspected spam link removed}

      The Merlin readme suggests to manually reset the router and enter the settings after every 3 firmware updates.

  20. I installed the latest Merlin firmware for the AC88U. A message popped up saying to manually reboot the router.
    I did this but.now I can’t find the router admin login page. When I try router.asus.com all I get is a blank white page saying scripts.affiliatefuture.com.
    I tried the IP address in the guide and that doesn’t work either. How do I find the correct addres to get back in

  21. I had been running Merlin that was about 6 months old, so decided to update to RT-AC68U_386.1_2.zip. Well, now I can’t get into the router. When I go to, I just get a white screen in my browser (Firefox). So no menu, no way to downgrade, can’t access. What should I try next?

  22. – Great article.
    – However in regards of Merlin on AIMesh nodes, here is Eric Sauvageaus own words:
    “While Merlin-based nodes seem to work fine so far, there is generally little benefit in running it on a node, so it’s generally recommended to leave your nodes on the stock Asus firmware.”
    ( https://github.com/RMerl/asuswrt-merlin.ng/wiki/AiMesh )
    – Hence it is a bit misleading in your article to advise Merlin on all nodes.

    • Thanks, Torbjorn. I don’t work with Eric. What I described was my experience. As I mentioned, mixing the firmwares is fine, but you’ll likely have minor issues (like with the firmware update).

  23. I have a question, Dong re: 86U, the file is w format not trx does it matter? also in changelog it says partition jffs, what’s about it? Do I need to do that

    I have latest asuswrt firmware releases on Jan 11,2021

    Thx any help is appreciated

    • You don’t need to use Merlin, Hresch. But if you want to use it, it’s a better idea to spend some time and educate yourself on what jffs (and many other things) mean, but you can ignore it. To answer your question, the file type of the firmware file doesn’t matter.

  24. Dong! thanks to your advice and reviews, I’ve purchased an ASUS rt-ax88u, it runs amazing with a gigabit connection. Still, I want to get into AiMesh, the signal strength in the basement is weak. Any advice on what Asus router I should use as the Node?


  25. Three months later and I am complaining about your idea of what firmware is?
    Maybe not great but still, your explanation is WAY OFF BASE.

    Firmware is just the same as software. It could be an OS or just a set IO controls like BIOS. What makes it FIRM rather than SOFT is the fact that it is “burned” onto a chip, so that it is “hardware” not “software” but with PROM technology even that distinction is blurred as you can, and do, “reburn” your firmware chips regularly.
    Your idea of an OS sounds more like a UI than an OS.
    You could burn an entire OS, and include a UI, onto a PROM an have it all in firmware.

    • Thanks for the input, Don. I love it when somebody complains. I mean it.

      But take another read at the post. I clearly stated that firmware is low-level and has direct access to the hardware. That’s way easier for anyone to understand than saying it’s “burned” onto a chip, which is not exactly correct, to begin with. (And then I would have to explain what a chip is, too.) I was busy trying to make folks have an overview of what firmware is vs. OS (which, by the way, always accompanies any new computer you buy) than trying to show off what I know. And the post wasn’t about firmware in general but mostly about a particular one.

  26. Hi, I installed Merlin on Asus RT-AX86U. But I am unable to config VPN. I tried talking to the representatives of VPN provider but still no luck after spend 3-4 hours.. Any advice, suggestions or solutions? Thanks in advance.

    • You made me laugh, Jai. To get help, you first need to know HOW to ask for help first. Judging from the way you asked the questions, I think it’s best to hire a professional to your house who can see things and figure stuff out for you. 🙂

      • I am sorry about that. I am new in this field with limited knowledge. Seeing your post, thought to ask. Apologies..

  27. Appreciate the article and am looking to update my Asus RT-AX58U. I do have a second RT-AX58U as a node. It is unclear to me how to update the node first as you indicated. How do I flash the node when I cannot login into it directly?

    • You do that via the router unit’s Interface, Stuart. The step is the same as mentioned in this post, just click on the Upload link of the node (instead of the router.)

  28. After reading the forums it looks Like even with Merlin the ASUS routers cannot have more than 16 devices assigned to parental controls or be blockable at any one time.

    I need a great router with a mobile app, vpn client capabilities, and support for many more devices in parental controls that can be blocked by a schedule and by a command or switch. Please point me in the right direction. A more business oriented device is fine if it can do what I need.

      • Good morning Dong,

        Thanks for replying. I’m not sure where your thought process lies regarding the MAC address comment. With 4 kids from 7 to 18 in the house, they have a lot of devices in the house to use to create distractions. Computers, laptops, tablets, phones, game systems, VR headsets, the list goes on. And there are some last gen phones, game systems and usb wifi adapters as well. I could get by with a 32 device limit for parental controls, but this information is very hard to find. I’m still not 100% sure what the new limits are for ASUS GT-AX1100. I thought I read that the new generation would support 64 devices in parental controls but now I can’t find that information again. I bought a RT-AX92u under that impression but I was mistaken the limits are still 16.

        Ubiquiti told me there is no limit in their OS but I think you mentioned it was sparcely featured. but they have a mobile app.

        The other feature that is a must is the VPN client which can route selective hosts via the VPN. VPN Fusion from ASUS has worked well, and Merlin has it via Entware on its supported devices.

        If I have to forgo a mobile app to get what I need I will have to, but these other 2 features are a must. Any direction you may have is really appreciated.

  29. Great article as usual. I had Merlin on a previous router and would LIKE it on my current AC88U, but I have two AIMesh nodes. It wasn’t clear to me if the nodes will automatically update along with the router or if there are other steps although the article seemed to indicate it works with the nodes. Can you clarify for me?


    • Not automatically, Tom. You can upgrade the nodes first if they support Merlin, then the router.

      • Ach, I’m probably screwed, my nodes are RP AC-1900 so not supported? How much of a hassle is it, or does it even work, to run Merlin on the router and ASUSWRT on the nodes? IF it worked, one would have to upgrade nodes manually from then on?


        • Not much of a hassle to get it work, Tom. And yes, you just need to update the node manually as I mentioned OR revert the router to Asuswrt, update the node, then put Merlin on it again. You can back up the settings and restore before and after. Not that bad.

  30. To your point on firmware vs. OS, one note is that Merlin allows you to use Entware which includes 2500+ linux packages easily installable via a package manager (okpg). Hook up a USB drive and you have a credible little Linux box on your hands. Recently I ran across an addon that let’s your run scheduled speed tests (so you can see how slow your cable provider really is…) and includes a nice little UI (https://github.com/jackyaz/spdMerlin).

    Like @ChuckD, I’ve been running it for a while and it has been flawless.

    • Thanks for sharing, Jim. Yeap, I’m aware of Entware but just didn’t want to be overwhelmingly geeky and get into a territory that’s very hard to explain in layman’s terms.

      • HEllo Dong.. thanks a lot for all your explanations… perfect, simple, very cool. Is it possible for you to do the same with the utilisation of “amtm – the Asuswrt-Merlin Terminal Menu”. It will be very very interesting for a lot if guys. Thanks a lot

  31. I ran Merlin on my AC68U for five years or so in a household environment and was very pleased with how it did. I especially liked the fairly frequent updates as they often dealt with security issues.
    Be sure to throw Eric some change too, he’s a dedicated volunteer!

    • Merlin software often released with bugs and security issues. It’s best to avoid it for daily use.

      • That may be your experience, but certainly not mine.
        And as someone who just retired from 24 years in IT, with several of those doing strictly cybersecurity, frequent updates (with thorough release notes, and an active community forum) tells me someone’s paying attention and responsible for the software’s upkeep.
        As opposed to the Android system on my phone…

        • Appreciate your input, Chuck. You’re probably right. Still, I’ll update the post if I run into anything unusual. In any case, the firmware is an option, and you can always revert back.

          • I’m writing this on a Macbook Pro… running Windows 11. 🙂

            Seriously, in terms of options, customizability (and other things) Apple is the worst.

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