What does CheckNet’s speed test measure?

CheckNet’s speed test measures your connection to the nearest Cloudflare data centre and gives four numbers: ping, the round trip of a small packet (the median of several tries); jitter, how much the ping goes up and down from one try to the next; and download and upload speed in megabits per second (Mbps).

Low ping matters for online games and video calls, low jitter for calls without dropouts, and download speed for video and files. A connection can be fast and still bad for calls if its ping or jitter is high.

Mbps or MB/s?

Providers quote speed in megabits per second (Mbps), but download apps usually show megabytes per second (MB/s). A byte is eight bits, so an 80 Mbps line downloads at most about 10 MB/s. CheckNet shows both numbers.

Find the cause, step by step

1. Pause every download, update, video stream and cloud sync on every device at home, and run the test again.
2. If you can, connect the device to the router with a cable and test. If the cable is fine and Wi-Fi is not, the problem is the Wi-Fi.
3. On Wi-Fi, test next to the router and then in your usual room. Walls and distance cut speed; moving the router or using the 5 GHz band helps.
4. Turn the router off, wait half a minute and turn it back on.
5. Test from another device. If only one device is slow, the problem is that device, not your internet.
6. Test at different times of day. If it is slow only in the evening, your provider’s network fills up at peak hours.
7. Test once with the VPN and once without. A far-away VPN server raises ping and lowers speed; pick a closer server.
8. Write the results down with the date and time. If it is still below your plan’s speed on a cable without a VPN, contact your provider’s support and give them those numbers.

A full router queue (bufferbloat)

If ping is fine when idle but jumps several times higher while downloading or uploading, the router holds packets in a long queue. The result is dropped calls and laggy games whenever someone else at home downloads. Some routers have an option called “quality of service” (QoS) or queue management; turn it on and set its speed limit a little below your line’s real speed.

One test alone says little. Run three in a row and go by the middle result.

Check again with CheckNet

After each change, run CheckNet’s “Speed test” page again and compare the numbers with before. If ping and jitter dropped but download is still low, the limit is your provider’s line; if only Wi-Fi is bad, move the router or replace it.