On very fast connections, a test can use up to about 1 GB of data.

START TEST

How does this test work?

• Ping: time for a small request to reach our server and start being answered (median of 20 samples). Jitter is how much that time varies (the slowest sample is left out, so one random delay does not distort it). It is HTTPS latency, so it can differ from other tools.
• Download / Upload: several parallel transfers for up to about 6 seconds each. The first 1.5 seconds (less on very fast connections) are ignored while the connection ramps up.
• Servers: download, upload and ping are measured against calculatest's own server. To use the line fully, several connections are opened at once.
• ms loaded: latency measured while downloading or uploading. A big jump means your router or modem buffers are filling, and calls or games may lag when someone uses the connection.
• Network and Server: the internet provider network your IP address belongs to (it may differ from the brand name you know) and the location of the server that answers the test. They are shown only to you on this page.
• Connection: the type (Wi-Fi, mobile data...). Many browsers do not report it, especially on computers and iPhone. Browsers never reveal the name of your Wi-Fi network.
• Notes under Download and Upload: each result shows one or more of these notes.

  Note	What it means
  complete	Ran the full time, with no limits or errors.
  stable speed	Ended early because the speed was already steady.
  limited data	Stopped at the data limit. The result is still valid.
  backup server	The main server did not answer, so a backup was used. It may be less accurate.
  N errors	Some upload requests failed and were repeated. N is how many failed.
  test failed	That part could not be measured. Try again.
  cancelled	You stopped the test before that part was measured.

• Cancel: while the test runs, the button turns into Cancel test and you can stop the test at any moment. What was already measured is kept, and the rest shows cancelled.
• limited data: to save data, each phase is limited to about 400 MB (about 800 MB for the whole test; about 600 MB on mobile data when your browser reports it). On very fast connections the phase stops at that limit and is measured for fewer seconds. The result is still valid, but it can be a little less stable.
• stable speed: on fast connections, the phase ended early (after at least 350 MB, or 250 MB on mobile data, and only when it saves several seconds) because the speed was already steady, so there was no need to use more data.
• backup server: the main server did not answer and a backup one was used, so the result may be less accurate. errors: some upload requests failed and were repeated. test failed: that part of the test could not be completed; try again.
• Different from other speed tests? Each test uses its own servers and method, and on Wi-Fi your device and network also matter. For the best result, stand close to your router and run it two or three times.
• A full test usually uses up to about 800 MB of data. On very fast connections it can use more, but it stops before consuming 1 GB. Results may vary by device, browser and network.
• Debug modeOFF
  Shows technical details of the test, for troubleshooting. The page reloads when you switch it.