Technical specifications of download test
Our speed test downloads packets of data over an HTTP connection and measures the time the transfers take, in order to work out a download speed in Mbps (Megabits per second).
A small initial file is downloaded in order to gauge an approximate speed of the connection. Based on this result, the speed test selects a larger file to perform the main download test.
For example, on a slower connection the speed test might choose a payload of 2MBs, but on a faster connection it may select one of 10MBs. This enables the speed test to scale and accurately measure all types of connection, from slow ADSL to very fast fibre-optic connections.
Additionally, the test simultaneously requests multiple files to download at once. This causes the user's bandwidth to be saturated, providing an accurate picture of their download speed capacity.
For this reason, we suggest that users turn off wireless connectivity for any other devices, as well as not running any data-heavy programs at the time of the test, in order to receive the most accurate results for your line's speed.
Technical specifications of upload test
Our internet speed test submits packets of data over an HTTP POST connection and times how long the transfers take, in order to work out an upload speed in Mbps.
The test submits multiple packets at the same time. This causes the user's bandwidth to be saturated, providing an accurate picture of their upload speed capacity.
What is the speed test’s capacity?
The speed test has been built to test broadband download speeds up to - and above - 100Mbps.
It works with the UK's fastest broadband services, including Virgin Media, BT Infinity and fibre broadband products from the likes of TalkTalk and Sky.