The best broadband speed tests
Want to test your broadband speed? We reveal which speed test sites and services you can trust to deliver accurate results
There are dozens of websites that claim to reveal the true speed of your broadband connection, but few that deliver truly accurate results. Many such speed testers use a single, tiny data payload to test the speed of your connection, which may provide unreliable readings.
However, there are several good speed test sites and services out there, run by experienced professionals who know what they’re doing. Here’s our pick of the internet speed testers, with details on how they test the speed of your connection and the results they offer.
Speedtest.net offers a variety of ways to test your broadband speed. The main Speedtest.net website asks you to choose one of about 20 UK speed test servers to ensure that your results aren’t affected by long-distance data transfers, as they might be with sites hosted in the US or Asia.
Once you click on a local server the test begins automatically, measuring the download and upload speed of your connection, as well as the ping rate. The ping rate measures how long it takes for a tiny packet of data to reach and return from the test server, giving an indication of how responsive your connection is, which is critical for online gaming and services such as VoIP. Fixed-line broadband connections will normally have a much faster ping rate than mobile services, and you’ll want a ping rate of no more than 50-60ms for responsive gaming. (Speedtest.net operates a separate Pingtest.net site for those who want further details on factors such as ping, jitter and packet loss.)
Speedtest.net initially sends a small batch of files to your test system to get an initial indication of how fast your connection is. Based on these results, it then sends a series of larger files to more accurately measure the download speed for around 10 seconds; high-speed fibre connections will be sent more test data than those on sluggish ADSL connections, considerately ensuring that the speed test doesn’t bog down those on slower lines. The site uses up to four simultaneous download streams to fully saturate the connection and get an accurate measurement of its potential. The upload speeds are then measured in a similar fashion.
You don’t have to use a PC to measure your speeds with Speedtest.net. The site has excellent mobile apps for Android and iOS, which can be used to measure both your fixed-line speed (using Wi-Fi) and 3G/4G connection speeds. The mobile app automatically collates your results, so you can tell if your connection speed is falling or improving over time.
Thinkbroadband recently updated its long-established speed test, moving from a Java-based app to a new Flash-based service. That means it won’t run on most mobile devices, although Thinkbroadband does have a dedicated Android app.
Thinkbroadband asks users to enter their postcode and select their ISP before running a test, although neither piece of data is mandatory – the data is used to help map broadband speeds and rate the performance of ISPs.
The Thinkbroadband test uses six different HTTP streams to saturate the connection and measure download speeds, as opposed to Speedtest.net’s four. The test checks to see all six threads are working, and restarts automatically if one thread fails, to ensure the accuracy of its results.
Thinkbroadband delivers two different download results: a burst speed and an average speed. The burst speed shows the maximum speed achieved throughout a small section of the test. To complicate matters further, the site delivers burst and average speeds for single and six thread tests. Thinkbroadband also delivers a ping result, although here it’s expressed as "latency".
Our final speed test service is a different beast to the other two. SamKnows Broadband is the company behind the official broadband speed results published by regulator Ofcom. Instead of using a web-based test, SamKnows sends out "whiteboxes" to thousands of volunteers across the country, which monitor line speeds over time and provide detailed performance metrics to the user, SamKnows and the ISPs themselves.
The whitebox is a small diagnostic device that connects to your home router. It only runs speed tests when the internet connection isn’t in use, ensuring that your regular internet activity isn’t affected, and that there’s no unfair interference with test results, which is crucial when Ofcom is comparing the performance of different ISPs.
Detailed upload, download, ping and other data is collected and made accessible to the user in a variety of ways. There’s a web dashboard that displays historical results, as well as mobile apps for iOS and Android, and a monthly report that’s emailed to the user.
If you wish to volunteer for the tests and receive a free whitebox, you can sign up here on the SamKnows site. Note that you have to be a customer of one of the major ISPs, and that the whitebox will download roughly 3GB of data every month, so is best avoided if you’re on a broadband package with a tight data cap. Volunteers aren’t guaranteed to be admitted, although SamKnows plans to start selling the whiteboxes for personal use – you can register your interest here.