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We’ve written the following answers to questions frequently thought, but rarely asked, about knowing how the speedtest works.

Use the broadband speed check to get a snapshot of your current download and upload speed. There's no charge, so do as many tests as you like – in fact, we encourage you to do as many as you can (and at different times/days) to build a more accurate overall picture of the speeds you are getting.

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Even if you run lots of them, remember broadband speed tests may still not be a definitive answer to what pace your broadband connection runs at, or is actually capable of. Please see both our guide to why your broadband connection may be slow and our guide to broadband speeds.

This test is designed for broadband connections of all types, including mobile broadband and smartphones, and is compatible with all major web browsers on desktop, mobile and gaming platforms.

How does the broadband speed test work? 

Our broadband speed test measures the amount of data transmitted over the connection divided by the duration of the test to calculate the speed of the connection. This provides a simple, clear, real-world measurement of broadband speed. 

The test provides accurate measurements of download and upload speeds for any type of broadband connection by dynamically assessing the speed and automatically adjusting in order to achieve the maximum throughput of the line.

Data transferred during the test is not saved to your computer.

Is the broadband speed checker free?

The Broadband Genie internet speed test is completely free. We feel it's important to offer you all the broadband comparison tools you need in one place, so you can check your speed and use your postcode to look for deals that may offer you better value for money, as well as a faster internet connection.

What is the best way to test internet speed? 

Before using the broadband speed check you should close all other programs and disconnect or switch off any other devices in your household. 

When possible, connect the device being tested directly into the router with a network cable. If using Wi-Fi you should stand next to the router and not use any signal boosters.

Speeds can vary during the day, so test at different times to get a more accurate picture of your broadband speed.

Why is the speed I get different than the speed advertised?

There are a number of reasons why the speed test may report a different figure to the speed advertised when you signed up for the broadband.

First of all, the publicised speed is never guaranteed. Home broadband is advertised with an “average” download speed which is achieved by at least 50% of customers, but of course your connection could be slower (or faster) than average. 

Meanwhile upload speed is still allowed to be advertised with an “up to” figure which represents the maximum possible rate but which is unlikely to be achieved in practice. The same applies to mobile broadband (both download and upload). 

But in addition there are other reasons why the connection might be slower than expected. Software running on your device and other users sharing the connection will all impact the test. Wi-Fi can be slower than a cabled connection, while poor house wiring can affect home broadband speeds (try to be sure your router is plugged into your main incoming socket). Your supplier may also prioritise different types of broadband traffic. And mobile internet is heavily dependant on having a strong signal, and can be noticeably slower in busy areas. 

Why isn’t the test working in my browser?

The test uses pure HTML5 and does not rely on Java or Flash. This allows it to operate on most modern web browsers and devices, including computers, tablets, phones and games consoles. 

If you find that the test is not working you should try disabling any extensions/addons which may interfere (use your browser’s “Safe Mode” if available). Failing that, try the test in a different web browser.