ASUS RT-BE55 vs RT-BE90U: Which WiFi 7 Router to Buy

The ASUS RT-BE55 and the ASUS RT-BE90U are both WiFi 7 routers with AiMesh, a 2.5G WAN port, and ASUS's usual VPN and parental-control tools. The BE90U is the larger, more expensive one. It adds a 6 GHz radio, three 2.5G LAN ports, and a USB port. The BE55 stays on 2.4 and 5 GHz, and every LAN port is gigabit.

Specs below are from ASUS's RT-BE55 tech specs and RT-BE90U tech specs. The full write-ups are the RT-BE55 review and the RT-BE90U review. If you are also looking at NETGEAR or the ROG model, the wider WiFi 7 comparison covers those.

The short answer

Buy the RT-BE55 when the devices you actually use are fine on 2.4 and 5 GHz, and gigabit Ethernet is enough for anything you plug in.

Buy the RT-BE90U when any of these is true:

• A phone, laptop, or desktop can join 6 GHz (WiFi 6E or WiFi 7).
• A NAS, desktop, or switch should run at 2.5 gigabit on the LAN.
• You want a USB port for a shared drive or a 4G/5G backup stick.

One yes is enough. The 6 GHz radio is unused if nothing in the house can see it, and the 2.5G LAN ports are unused if every wired device is still gigabit.

The renders above are official ASUS shots, and they are not to scale. The BE90U is the bigger router: 320 mm wide and 761 g, against 238 mm and 446 g for the BE55.

Specs side by side

Those wireless rates are ASUS's combined theoretical figures. A laptop across the house will not see 9,400 Mbps. What changes in a real house is which band the laptop is allowed to use, and how fast a cable plugged into the router can go.

The BE55's processor is clocked higher (2.0 GHz against 1.5 GHz). The BE90U has twice the RAM, twice the flash, and a third radio. Clock speed on its own does not make the cheaper router the faster one.

The 6 GHz band

This is the whole wireless difference. On 2.4 and 5 GHz the two routers are rated the same: 688 Mbps and 2,882 Mbps, both 2x2, both with 4096-QAM. A WiFi 6 phone that cannot use 6 GHz gets the same class of radio either way.

The BE90U's extra radio is rated at 5,764 Mbps on 6 GHz, with channels up to 320 MHz. ASUS's product pages list Multi-Link Operation on both routers. On the BE55 that means combining or switching 2.4 and 5 GHz. On the BE90U it can include 6 GHz as well. Which MLO mode works depends on the client, and ASUS says so on both pages.

6 GHz is also the shorter-range band. It is at its best in the same room, or one room away, with a clear path. It is a poor reason to buy the BE90U if the only WiFi 7 device sits two floors up.

Ports, USB, and wired speed

Both routers have a 2.5G WAN port, so either one can take a multi-gig internet plan from the modem or ONT. They diverge on everything else you plug in.

The BE55 has four gigabit LAN ports and no USB. A 2.5G NAS or desktop plugged straight into it tops out at 1 gigabit. Internet faster than 1 gigabit still arrives on the WAN port, then gets shared out over WiFi or split across those gigabit jacks.

The BE90U has three LAN ports, and ASUS rates those and the WAN port at 2.5 Gbps. The back panel groups them under a 2.5G label. That is the right layout for a 2.5G NAS, a desktop, and a small multi-gig switch. There is no 10G port on either router. A 10-gigabit home lab needs a different box, or a switch in front of one of these.

The BE90U's USB port is USB 3.2 Gen 1 in the spec sheet. The port itself is labeled USB 3.0, which is the same 5 Gbps generation. ASUS lists storage sharing, printer sharing, and 4G/5G tethering for it. The BE55 has nowhere to plug any of that in.

Software

The day-to-day interface is the same idea on both: ASUSWRT in a browser, or the ASUS Router app. Both do AiMesh as a main router or a node, so you can add a compatible ASUS router later instead of replacing the system. Both include a VPN server and client (WireGuard, OpenVPN, and the older protocols), Instant Guard, and VPN Fusion. The BE90U spec sheet also names Surfshark and NordVPN.

Parental controls on the BE55 are time scheduling, safe browsing, and a custom schedule. The BE90U adds web and app filters, and ASUS lists up to 64 parental-control profiles.

AiProtection is included on both, with no subscription in the spec sheets. The feature lists are not identical. The BE55 page includes router security assessment, malicious-site blocking, two-way IPS, and infected-device blocking. The BE90U page includes security assessment and two-way IPS, and the product page calls that package commercial-grade AiProtection. Treat those as the published lists, then turn on whatever the firmware actually shows during setup.

The BE90U also has repeater mode. The BE55's listed modes are router, access point, and media bridge, plus AiMesh node.

Which one to buy

RT-BE55. A house full of phones, TVs, and smart-home gadgets, on an internet plan around a gigabit or below, with nothing that needs a 2.5G cable. You still get WiFi 7 features on the two bands you already use, a 2.5G WAN port for later, and AiMesh if one router is not enough. Our RT-BE55 review goes further into the software.

RT-BE90U. You already own a WiFi 6E or WiFi 7 laptop or phone, you are about to, or you want 2.5G on the wired side. The extra money is paying for the 6 GHz radio, the faster LAN ports, the USB port, and more RAM. Our RT-BE90U review covers that router on its own.

A different ASUS router. If you need more than three 2.5G LAN ports, look at the ROG Strix GS-BE12000 instead of stretching the BE90U. If you want the cheapest dual-band WiFi 7 box and you do not care about AiMesh, the wider comparison includes the NETGEAR RS90.

Where to buy