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◆Speed Test for WiFi Testing guide

One Test Tells You Nothing. Three Tests Tell You What Is Slow.

A single Wi-Fi speed test mixes your plan, router, coverage and device into one number. Here is the three-test method that separates them, and how to read download, upload, ping and jitter.

Speed Test for WiFi Editorial Team

A speed test run on a phone in the kitchen produces one number, and that number blends at least four things: the speed your provider delivers, your router, how well Wi-Fi reaches that spot, and the phone itself. If the result is disappointing, it cannot tell you which of those is at fault. Running three tests in a deliberate order can.

Before you test

A fair test removes the noise first:

  • Pause other traffic. Stop large downloads, cloud backups, game updates and video streams on other devices. A 4K stream alone can use 15 to 25 Mbps.
  • Use a capable device. Older phones and laptops may top out below your plan’s speed, especially on Wi-Fi. Note the device and its Wi-Fi standard (Wi-Fi 5, 6, 6E or 7) with each result.
  • Pick a nearby server. Most test sites choose one automatically. Keep the same server between tests so the results compare fairly.
  • Run each test two or three times and keep the middle result. Single runs vary.

Test 1: on a cable

Connect a laptop or desktop to the router with an Ethernet cable and run the test. This is the closest you can get to what your provider actually delivers, and it is the figure your plan’s advertised speed refers to. Check that the computer’s Ethernet port supports the speed you pay for: a port limited to 100 Mbps will cap a 500 Mbps plan at around 94 Mbps.

If this result is well below your plan at several times of day, the problem is upstream of your home network, and it is worth contacting your provider with the numbers.

Test 2: on Wi-Fi, next to the router

Disconnect the cable and run the test over Wi-Fi in the same room, with a clear line to the router. This shows the best your Wi-Fi can do. Expect some loss compared with the cable: modern Wi-Fi 6 routers and devices can come close to wired speeds on fast plans, while older equipment may deliver half or less.

If this result is far below the wired one, look at the router and the device: make sure you are on the 5 GHz or 6 GHz band rather than 2.4 GHz, and check whether the router or device only supports an older Wi-Fi standard.

Test 3: on Wi-Fi, where it feels slow

Now run the test in the room where the problem happens. The gap between test 2 and test 3 is what distance, walls and interference are costing you. A drop from 400 Mbps to 40 Mbps between rooms is a coverage problem, not a provider problem, and no plan upgrade will fix it. Moving the router higher and more central, reducing the walls in between, or adding a mesh node or wired access point usually will.

Reading the results screen

Download (Mbps). How fast data reaches you. Speeds are quoted in megabits per second. Divide by eight for megabytes per second, the unit most download dialogs use: 100 Mbps is about 12.5 MB/s.

Upload (Mbps). How fast you send data, which matters for video calls, cloud backups and sending large files. On cable and many DSL plans, upload is much lower than download by design; on fibre it is often the same.

Ping or latency (ms). The round-trip time to the test server. Lower is better. Around 20 to 50 ms is comfortable for calls and most online games. Some tests show both idle latency and loaded latency, measured while the connection is busy.

Jitter (ms). How much latency varies from moment to moment. High jitter causes choppy calls and game stutter even when download speed is high.

Loaded latency. If latency jumps from 20 ms idle to several hundred milliseconds under load, your connection suffers from bufferbloat: the router or modem queues too much data when the line is busy. Enabling Smart Queue Management (SQM) or a similar quality-of-service feature on the router, if it has one, often fixes it.

When a VPN is on

A VPN routes your traffic through the provider’s server, so a speed test measures the whole path, including the VPN. Expect some reduction in speed and an increase in latency, larger if the VPN server is far away. To judge your home connection, test with the VPN off; to choose a VPN server, compare results with it on.

The short version

Test on a cable, then on Wi-Fi beside the router, then on Wi-Fi where it is slow. The first result is your internet, the gap to the second is your Wi-Fi equipment, and the gap to the third is your coverage. Fix whichever gap is biggest.