Why Is My Wi-Fi Slow? Bands, Standards and What to Fix First

Why Wi-Fi is slower than a wired connection

With a wired LAN cable, one device uses one cable. With Wi-Fi, every device connected to the router shares the same radio channel. If family members' phones or a TV are using the connection at the same time, each device gets a smaller share of the speed.

Radio signals also get weaker the farther they travel and the more walls and floors they pass through. When the signal gets weak, the router and the device may switch to a slower way of sending data that is more likely to get through, and the speed drops. Overlap with neighbors' Wi-Fi and other household devices, called interference, is another cause of slower speeds.

In short, your Wi-Fi speed is decided by three things:

• Signal conditions: distance, walls and interference
• Equipment: the standards and number of antennas your router and device support
• How many devices are connected at once: how many others share the signal

If you want to know the speed of the connection itself, the most reliable way is to test from a computer connected by cable. What the four numbers in a result mean is explained in internet speed guidelines.

2.4 GHz vs 5 GHz vs 6 GHz

Wi-Fi uses three frequency bands (different kinds of paths for the radio signal). On routers whose SSID (network name) includes a band label, you can tell from the name which band you are connected to. If you cannot tell, check the router's settings page or the Wi-Fi details screen on your device.

The higher the frequency, the shorter the wavelength, and the harder it is for the signal to bend around obstacles. So at the same transmit power, 5 GHz and 6 GHz tend to reach a shorter distance than 2.4 GHz.

The basic rule is: in the same room as the router or the room next to it, use 5 GHz or 6 GHz; in a room farther away where 5 GHz is unstable, use 2.4 GHz. To use 6 GHz, both the router and the device must support Wi-Fi 6E or later.

Wi-Fi standards and their theoretical maximum speeds

Each generation of Wi-Fi has a name such as "Wi-Fi 4" or "Wi-Fi 5". The IEEE name is the official number given by the IEEE, the organization that sets the standard.

The "theoretical maximum" in the table assumes the widest channel and the largest number of antennas (streams). It does not mean a single phone can reach that speed. Real speeds also change with signal conditions and the number of devices connected at the same time.

Looking at actual product specs makes the gap clear. For example, the 5 GHz spec of Buffalo's Wi-Fi 6 router WSR-3200AX4B is listed as "802.11ax: 2401Mbps (80MHz 4x4)", and the spec sheet notes that this is a theoretical maximum and does not indicate the actual transfer speed. An Intel document also states that a Wi-Fi 7 client with 2x2 antennas that supports 320 MHz channels, 4096QAM and Multi-Link Operation has a theoretical maximum of 5.76 Gbps (a value based on the draft standard).

The 320 MHz channels of Wi-Fi 7 are available in the 6 GHz band, and Wi-Fi Alliance describes Wi-Fi 7 as offering twice the throughput (the amount of data actually carried) of Wi-Fi 6.

How distance, walls and floors affect speed

Wi-Fi speed changes a lot depending on where you are relative to the router. These conditions have the biggest effect:

• Distance: the farther you are from the router, the weaker the signal and the lower the speed.
• Walls, doors and floors: concrete walls, metal doors and drywall can all make it harder for the signal to get through. The same applies when a floor or ceiling is in the way.
• Floors of the building: using a router on the ground floor from the second or third floor means the signal has to pass through floors and becomes weaker.
• Router placement: placing the router directly on the floor, inside a closed cabinet, behind a sofa or in a metal cabinet makes it harder for the signal to reach you.

Even in the same home, it is common to get plenty of speed near the router and a "Too slow" result in a room farther away. When comparing speeds, always note which room you tested in.

Your phone or computer sets the upper limit

Wi-Fi speed is set by whichever is less capable, the router or the device. Even if you buy a Wi-Fi 7 router, a phone that only supports up to Wi-Fi 6 will connect using Wi-Fi 6.

You can check which standards a device supports in the "Wireless" or "Wi-Fi" section of the manufacturer's spec page. For example, Apple's technical specifications list the iPhone 11 as "802.11ax Wi-Fi 6 with 2x2 MIMO" and the iPhone 16 as "Wi-Fi 7 (802.11be) with 2x2 MIMO" (Wi-Fi 7 only in supported countries and regions). 2x2 MIMO means the device uses two antennas each for sending and receiving.

For a computer, check the specs of the built-in wireless adapter or of the USB Wi-Fi adapter. If you are using an old adapter, its standard becomes the upper limit even when the router is new.

What is a good Wi-Fi speed?

Results measured over Wi-Fi can be read with the same thresholds as this site's speed test.

On Wi-Fi, ping and jitter sometimes get worse before download speed does. Even if your download is "Plenty", jitter of 30 ms or more means meeting audio and games are likely to be unstable.

The "average Wi-Fi speed" varies so much with the location, device and connection that comparing your numbers with other people's is not very useful. Comparing within your own home is more reliable. Test in these three places:

1. A computer connected by cable (the speed of the connection itself)
2. A phone 1–2 m from the router (close to the upper limit of your Wi-Fi)
3. A phone in the room you usually use (the speed you actually get)

If there is a big gap between 1 and 2, the cause is likely the router or device standards. If there is a big gap between 2 and 3, distance or walls are the likely cause. If all three are slow, suspect the connection itself and go through the steps in why your internet is slow.

How to increase Wi-Fi speed, step by step

Trying the fixes that cost the least money and effort first helps you avoid unnecessary purchases. After each step, test again in the same place to check whether it helped.

Mesh Wi-Fi is a system in which several units work together to create a single network. It suits "distance and walls" problems, such as a large home or one with several floors.

Even if you replace the router in step 3, the benefit is limited if your devices still use an older standard. Check the standards supported by the devices you use most before buying. Devices that never move are usually more stable on a cable. For fixes beyond Wi-Fi, such as restarting the router or switching to IPv6 IPoE, see how to increase internet speed.

This site's speed test uses no ads or third-party trackers and runs on the open-source LibreSpeed (LGPLv3). It automatically picks the server with the lowest ping from our own server in Sapporo and 37 public mirrors around the world (from Honshu in Japan, usually "Tokyo"). Test before and after each fix, in the same room and at the same time of day.

FAQ

How much Wi-Fi speed is enough?

Download of 30 Mbps or more and upload of 10 Mbps or more in the room you usually use is plenty for 4K video, online meetings and several devices at once. For HD video or meetings only, a download of 10–30 Mbps also works. Check ping and jitter as well.

Is my Wi-Fi broken if it is slower than a wired connection?

In most cases, no. Wi-Fi shares the signal among several devices and gets weaker with distance and walls, so a lower result than a wired connection is normal. If it is extremely slow even on 5 GHz near the router, check the standards your router and device support.

Should I connect to 2.4 GHz or 5 GHz?

In the same room as the router or a nearby room, 5 GHz is usually the better choice because it can reach higher speeds. In a distant room or on another floor where 5 GHz is unstable, 2.4 GHz, which gets through walls more easily, may be more stable. Testing on both and comparing is the most reliable way to decide.

Will a Wi-Fi 7 router make my phone faster?

If your phone does not support Wi-Fi 7, it can only reach the speed of the standard it does support. You can check this on the manufacturer's spec page. Also, a router's theoretical maximum is not necessarily the speed a single phone can achieve.

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