NOTE: Before you begin a speed test, it's important only one computer or device is online in your house when the test is carried out, so if you have flatmates or kids maybe wait until they go out or go to bed.

Data is sent from your computer to the test server over multiple connections to measure your maximum upload speed. The upload test run the same way as the download test, but in reverse. The goal is to send as much information as your connection can handle to accurately measure your download speed. If the test calculates your connection can handle more data, it will open up more connections to send even more information.

It does this by requesting a piece of reference data and measuring the real-time transfer speed. A speed test is a free web-based service that measures the speed, latency (delay) and jitter (difference in delay) of data sent between your computer or device and a nearby test server.Ī speed test first checks how fast your connection can download information.