1.A test moves a lot of data
WiFi Speed Test downloads data for about 10 seconds, then uploads data for about 10 seconds, over several parallel connections so it can reach the full speed of your line. The faster your connection, the more data the test uses.
2.How much data a test uses
The amount is roughly your speed multiplied by the test time, and each direction runs for about 10 seconds.
| Speed in that direction | Data used in 10 seconds |
|---|---|
| 5 Mbps | 6 MB |
| 25 Mbps | 31 MB |
| 100 Mbps | 125 MB |
| 300 Mbps | 375 MB |
| 500 Mbps | 625 MB |
| 1 Gbps (1,000 Mbps) | 1.25 GB |
| 2 Gbps (2,000 Mbps) | 2.5 GB |
Add the download and upload figures for the whole test. Latency checks add only a small amount on top. A single test on a symmetrical gigabit line can use about 2.5 GB, which matters if your plan counts in gigabytes.
3.Effect on other people and devices
While the test runs, it uses most of your available bandwidth. Video calls, streaming, online games, downloads and other devices on the same network can stutter or slow down for those 20 seconds or so. Run the test when nobody is relying on the connection.
4.What affects your result
- WiFi signal and band. Distance, walls and interference reduce speed. The 2.4 GHz band is slower and more crowded than 5 GHz or 6 GHz.
- Your device. Older WiFi adapters, power-saving modes and a busy processor can cap what the device handles.
- Your browser and extensions. Ad blockers, VPNs, antivirus filtering and many open tabs can lower results.
- Other traffic. Anything else using the connection is taken away from the test.
- The server. The test uses a nearby Cloudflare server. Distance and routing affect latency and sometimes speed.
- Time of day. Evening congestion on your provider’s network can lower speeds.
5.How to get a more reliable result
- Connect with an Ethernet cable if you can, or stand close to your router on 5 GHz or 6 GHz WiFi.
- Close other apps, tabs and downloads, and pause other devices.
- Turn off VPNs and proxies for the test.
- Use an up-to-date browser, ideally in a private window with extensions off.
- Run the test two or three times at different times of day and compare.
6.Why results differ from your plan’s advertised speed
Providers usually advertise a maximum (“up to”) speed measured under ideal conditions on their own network. Protocol overhead, WiFi, router performance and congestion mean real-world numbers are normally lower. A result far below your contracted speed on a wired connection, repeated at several times of day, is worth raising with your provider.
7.What the other numbers mean
- Latency (ping) is the time a small request takes to reach the server and come back, in milliseconds. Lower is better.
- Jitter is how much that latency varies from one request to the next. High jitter makes calls and games feel choppy.
- Loaded latency is latency measured while the connection is busy downloading or uploading. A large rise compared with idle latency points to bufferbloat in your router or provider.
- Streaming, Gaming and Video calls are plain-language ratings estimated from your measured speed, latency and jitter. They are indicative guides, not guarantees about any particular service.
8.No warranty on figures or data charges
The figures on this page are estimates to help you plan. We are not responsible for data charges, overage fees or throttling that follow from running a test. See the Terms of Use.
9.Contact
To ask a question about this document or to make a privacy request, contact the operator of this site.