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Asus RT-AX88U vs RT-AC88U: The Same Router of Two Wi-Fi Standards

Asus RT-AX88U vs. RT-AC88U is an interesting comparison since they are of two different Wi-Fi standards.

Right off the bat, it seems the former, the Wi-Fi 6 version, is a straightforward replacement of the Wi-Fi 5 counterpart. But is that the case? Find it all out in this post.

Asus RT-AX88U vs. RT-AC88U
The Asus RT-AX88U is almost identical to the RT-AC88U.

RT-AX88U vs RT-AC88U: Similarities

Just take a good look at them. They are almost identical. Indeed, these two routers share the same design, dimensions, weight, number of network ports (eight LANs and one WAN), and antennas. And there’s more.

On the inside, they both have the same set of features, including gaming, online protection, QoS, and so on. The two can also work together to create an AiMesh Wi-Fi system. (In this case, it’s best to use them via a wired backhaul.)

Most importantly, you can put Merlin firmware on both and turn them into much better Wi-Fi machines than what you get out of the box. The support for Merlin is among the main reason I’d consider these two.

Read this  Got One of These Asus Routers? Sprinkle on Some Merlin Firmware Magic!

Asus RT-AX88U vs RT-AC88U: Hardware specifications

NameASUS AX6000 Dual-Band 
Wi-Fi 6 Router
ASUS AC3100 Dual-Band 
Wi-Fi 5 Router 
ModelAsus RT-AX88UAsus RT-AC88U
Wi-Fi TechnologyDual-Band Wi-Fi 6 (802.11ax) AX6000Dual-Band Wi-Fi 5 (802.11ac) AC3100
Chipset ManufacturerBroadcomBroadcom
2.4GHz Wi-Fi Specs4×4 Wi-Fi 6: up to 1148 Mbps4×4 Wi-Fi 5: up to 1000 Mbps
5GHz Wi-Fi Specs4X4 Wi-Fi 6: up to 4833 Mbps4×4 Wi-Fi 5: up to 2167 Mbps
Supported Wi-Fi Standards802.11a/b/g/n/ac/ax802.11a/b/g/n/ac
AP ModeYesYes
Mesh-readyYes (AiMesh)Yes (AiMesh)
Channel Width Support20/40/80/160 MHz20/40/80 MHz
Gigabit LAN Ports8x Gigabit LAN, 1x Gigabit WAN8x Gigabit LAN, 1x Gigabit WAN
Multi-Gig PortsNoneNone
Link AggregationYes (LAN 1 and LAN 2)Yes (LAN 1 and LAN 2)
USB2 x USB-A USB 3.01x USB 2.0, 1 x USB 3.0
Mobile AppAsus RouterAsus Router
QoSYes (Excellent)Yes (Excellent)
Built-in Online ProtectionYesYes
Parental ControlYesYes
Merlin Firmware SupportYesYes
Gaming FeaturesWTFast Gamers VPN, 
Automatic Port-forwarding 
and QoS
WTFast Gamers VPN,
Automatic Port-forwarding
 and QoS
Processing Power1.8 GHz quad-core CPU,
 256MB Flash, 1GB RAM
1.4 GHz dual-core CPU, 
128MB Flash, 512MB RAM
Dimensions11.8 x 7.4 x 2.4 inches 
(30 x 18.8 x 6.04 cm)
11.8 x 7.4 x 2.4 inches 
(30 x 18.8 x 6.04 cm)
Weight2.1 lbs (945 g)2.1 lbs (945 g)
Hardware specifications: RT AX88U vs. RT AC88U

RT-AX88U vs. RT-AC88U: Differences

The most significant difference between the two is the fact the RT-AX88U is a more powerful router. For one, it uses Wi-Fi 6. It also has a faster quad-core CPU and doubles the amount of RAM and flash memory.

The RT-AX88U also has two USB 3.0 ports (instead of one 2.0 port) and, in my testing, delivered much faster network storage performance when hosting a portable SSD.

In many ways, the RT-AX88U supersedes RT-AC88U as it’s intended to be. However, the lack of a multi-gig port means, in reality, you likely won’t see much difference between the two in terms of network Wi-Fi performance.

RT-AX88U vs RT-AC88U: Performance

It’s expected that the RT-AX88U would outdo the RT-AC88U, and, for the most part, it did in my testing. However, having no multi-gig port, it wasn’t that much faster when working with Wi-Fi 5 clients.

By the way, I initially tested the RT-AC88U using only Wi-Fi 5. There was no Wi-Fi 6 when I reviewed it, and it doesn’t have support this standard anyway. (Wi-Fi 6 clients do work with Wi-Fi 5 broadcasters).

But like all Wi-Fi 5 routers, it works with Wi-Fi 6 clients, or the other way round — Wi-Fi 6 clients work with Wi-Fi 5 broadcasters.

In any case, for this post, I did some additional tests using 2×2 Wi-Fi 6 clients, which connected to the router at 867 Mbps of negotiated speed. That’s the ceiling speeds of 2×2 Wi-Fi 5.

RT AX88U vs RT AC88U

By the way, both routers can host network storage via a portable drive. But of the two, only the RT-AX88U can work as a mini NAS server. It had much faster NAS speeds, as shown here, thanks to the higher hardware specs.

RT-AX88U vs RT-AC88U: Ratings

Asus RT-AC88U's Rating

9 out of 10
Asus RT AC88U 1
Design and Setup


Fast Wi-Fi performance with excellent coverage

Tons of valuable features, including the ability to guard the network against online threats

Eight LAN ports with Dual-WAN and Link Aggregation

Excellent support for Asus's AiMesh

Merlin firmware support


Awkwardly placed USB 3.0 ports

Slow network storage speed when coupled with an external hard drive

Asus RT-AX88U's Rating

8.4 out of 10
RT AX88U 2
Design and Setup


Fast Wi-Fi performance

Tons of useful features

Eight network ports with Dual-WAN and Link Aggregation

Universal setting backup and restoration

Fast network-attached storage speed when coupled with an external drive.

Merlin firmware support


No multi-gig network port

Buggy firmware (at review)

Which to get

In many ways, the RT-AX88U is better than the Wi-Fi 5 counterpart. But it’s also much more expensive while sharing the same feature set.

So if you’re still having a lot of Wi-Fi 5 and legacy clients, the RT-AC88 is a better choice. Put the Merlin firmware on it, and you’ll be amazed by what it has to offer.

Read this  Wi-Fi 5 vs Wi-Fi 6: Why it's (Still) OK to Delay Upgrading Your Home Network

And then, when you’re ready to upgrade to Wi-Fi 6, keep it. It’ll still work great as an AiMesh node, especially if you have wired your home with network cables.

The RT-AX88U is also a great router. But unfortunately, the lack of multi-gig network ports means you won’t almost see its full potential. For that reason, you should consider the more affordable yet multi-gig-ready RT-AX86U instead.

Looking for more Wi-Fi solution matchups? Check them all out here.

Read this  Best Wi-Fi 6 Routers of 2021: Take One, or Two, Home Today!
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14 thoughts on “Asus RT-AX88U vs RT-AC88U: The Same Router of Two Wi-Fi Standards”

  1. Hi Dong,

    I’m considering getting a AX88U since I’m upgrading to a 1Ghz internet. I am not 100% since I’ve seen other posts where you recommend the AX86U instead. AX86U is not in stock and is a bit cheaper than the AX88U here in Australia, but AX88U is available if I buy it now. Should I wait and buy the AX86U or that won’t make any difference?

    Ps:. local file transfer via wireless is not a requirement. Wi-fi range and speeds are priority.

  2. Hi Dong,
    I’m having a hard time deciding between the ax88u and ac88u at a 100$ difference.

    I was pretty well set on the ac88u largely because of I read about how much you liked it 🙂 and don’t think I need wifi 6 just yet but I’m hesitant now after realizing it’s a 6 year old model. Do you think it’s possible Asus and/or Merlin stop supporting the ac88u anytime soon?

    Apart from longer software support the only other benefit I could think of with the ax88u is possibly better Synology nas speed due to the cpu/ram bump and maybe wifi 5 devices battery life improvements due to wifi 6 efficiency. What do you think?

    Thanks for all the great articles.

    • The NAS speeds mentioned are not of a NAS server but the routers’ USB ports when hosting a portable drive, Chris. I’d go with the AC88U. It’ll last you for years to come.

  3. AC88U wifi coverage range better than AX88U? I’m trying to determine which one of these have better WiFi range before making a purchase.

  4. At > $450 and limited standardization (at this point) among clients, AXE still seems to be a pipe dream. I’m considering a move from the AC88U to the AX88U for $250 RN on Amazon.

  5. In your hardware specification chart on the Wi-Fi Compatibility line, it indicates that both routers support 802.11ax…is this true? Also, the link aggregation of Lan 1 & Lan 2 are dynamic (LACP) and might not work if someone wants to connect to a device that uses static link aggregation only.

    • Yes, Bill. Wi-Fi standards are generally backward-compatible so old hardware is forward-compatible. More here. And no, the chart can’t hold ALL the details, which are where the devil is in.

  6. Although there are only currently 2×2 WiFi 6 clients, which makes testing their throughput limited, there’s another way to test the peak WiFi 6 capability of WiFi 6 routers.

    What to do is to use two WiFi 6 routers, and one of them in router mode and the other one repeater/client/media-bridge mode. So one router transmits and the other one receives. Assuming both routers have a multi gig port, you can connect computers to the multi gig ports and test lan transfers. I did exactly this, one WiFi 6 router in the main room, and the other one about 50 feet away. Using 80 MHz channels, the routers connect to each other at 2.4 Gbps. And iperf3 shows a cool 1.6 to 1.7 gbps transfer speed which is pretty damn good. No need to run a wire, although performance would be better (on wireless clients of the repeater if it has dual 5 GHz radios… just use one for backhaul).

    I tried using 160 MHz channels to test but that was a disaster. One router detects radar on the upper 160 MHz channel (the other one doesn’t detect any radar) and then when I use the lower 160 MHz channel the situation is reversed. So I had to stick to 80 MHz. But 1.7 gbps on 80 MHz isn’t too bad at all.

    • You can do the same thing using multiple 2×2 clients at the same time and adding the numbers up, Joey. I do that for some of my reviews. The issue is the repeatability of the tests which allows you to apply to all routers so that a fair comparison is valid.


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