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Why is my Wi-Fi slow?

Five checks that tell you whether the problem is the Wi-Fi, the router or your provider.

Last verified: 8 November 2026. Menu names and paths change with firmware, so check your model's manual if a step looks different.

The short answer

Slow Wi-Fi usually comes from one of five things: distance and walls, the wrong band, a crowded channel, something else hogging the connection, or a slow line from your provider. Testing next to the router and then in the slow room tells you which.

Check before and after each change with the speed test. Run it near the router and in the room where the problem is.

Five checks, in order

1. Is it the Wi-Fi or the line?

Run a test on a computer plugged into the router with a cable, or standing right next to it. If that is fast and the slow room is not, the line is fine and the problem is wireless. If it is slow even on a cable, skip to check 5.

2. Distance and obstacles

Wi-Fi weakens quickly through walls, floors, metal, mirrors, fish tanks and appliances. A router in a cupboard, behind a TV or at one end of the house is a common cause. See how to boost your Wi-Fi signal.

3. The band you are connected to

2.4 GHz reaches further but is slower and more crowded. 5 GHz and 6 GHz are much faster at short and medium range. If your phone shows a weak 2.4 GHz connection while you are near the router, rejoin the 5 GHz network or give the bands different names so you can choose.

4. A crowded channel or a busy connection

In flats and apartments dozens of networks can share the same channel. Changing channel can double your speed; see the best Wi-Fi channel guide. Also check for a device uploading in the background, such as a cloud backup, a game update or a security camera. If calls and games lag only while something else is busy, run the bufferbloat test.

5. Your provider

If a wired test is well below your plan, restart the modem and router, check for outages, and test at a few different times. Keep the results: a set of slow wired tests is what a provider's support team will ask for.

Quick fixes worth trying first

More guides

Questions

Why is my Wi-Fi slow but the internet is fast on a cable?

Then the line is fine and the wireless link is the bottleneck: distance, walls, a crowded channel or an old device. Move closer, switch to 5 GHz, change the channel, or add a mesh node or access point.

Why is my Wi-Fi slow at night?

Evenings are peak time. More neighbours on the same channels and more people on your provider's network both slow things down. If a wired test is also slow at night, the provider is congested; if only Wi-Fi is slow, try a less crowded channel.

Why is my Wi-Fi slow on my phone only?

Phones have small antennas and often stick to a weak 2.4 GHz connection. Forget and rejoin the network, turn off low-power or data-saver modes, check for a VPN, and make sure the phone's software is up to date.

Why is my Wi-Fi slow all of a sudden?

Something changed: a firmware update, a new device uploading in the background, a neighbour's new router on your channel, or a provider outage. Restart the router, check for big uploads such as cloud backups, and compare a wired test.

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