How to Test Your Internet Connection Speed

You may have bought a connection advertised as 1.5 Mbps, 5 Mbps, or 10 Mbps from your internet service provide, but the actual speed you can download and upload data at is affected by many factors. Find out the true speed of your internet connection with a free online speed test.
Published: Dec 19, 2007
Author: Jordan Running

Understanding connection speed

The speed at which you download files from and upload files to the internet depends on a lot of factors. You're limited, of course, by the absolute maximum speed of your internet connection--that is, the speed your internet service provider (ISP) probably advertises--but in practice your ISP almost certainly doesn't guarantee that you'll ever attain those speeds (read the fine print in your contract). Though a connection advertised as 3 Mbps, 5 Mbps, or 10 Mbps will probably be plenty fast for most uses, it's likely your connection's actual speed is significantly lower. Your actual download and upload speeds are also influenced by the computer--be it a web server or another person's PC, as in the case of P2P file sharing--you're connected to. If you're trying to download a file from a server with a slow connection, no amount of speed on your end will make that download go faster. Finally, your transfer speed might be affected by how many other people are using the same lines as you. If you have cable internet, for example, your speed will be better when your neighbors aren't all using their cable internet. Furthermore, on most connections your download speed and upload speed will differ significantly (usually in favor of the former).

Further complicating things is terminology, in particular the distinction between bits and bytes. Bandwidth, which is what service providers advertise, is typically measured in millions of bits--megabits--per second, e.g. 10 Mbps. Most programs that you use to access the internet, however, report transfer speeds in bytes per second. One byte is equal to eight bits--bytes are usually (but not always) denoted by a capital 'B,' whereas bits use a lowercase 'b.' So if your connection is delivering 4,000,000 bits per second (4 Mbps), the program you're using might report 500,000 bytes per second (500 kBps)--the two numbers are equivalent, but one seems smaller which, as you've guessed, is why ISPs prefer to advertise bits instead of bytes. Most speed-testing services will report your speed in kilobits or megabits per second--in order to translate that into what you can expect to see in, say, Internet Explorer, just divide by eight to convert to bytes.

Testing your connection speed

Since you can't trust your ISP to tell you the true speed of your internet connection, the only way to find it out is to test it yourself, and for that there are a number of web-based services to choose from. Before we begin, however, make sure you stop any active downloads (or wait for them to finish) and quit any bandwidth-hogging programs like file-sharing apps or internet radio. Now head over to my favorite speed-testing service, Speedtest.net, which is provided for free by Ookla Net Metrics, a company that specializes in measuring the speed of the internet.

Using Speedtest.net is very straightforward. Ookla maintains a fleet of speed-testing servers all over the world--just click on the one nearest you on the world map and the speed test will begin. First it will test your download speed by downloading data from the server to your computer (don't worry, nothing is stored on your computer permanently). Then it'll test your upload speed by doing the opposite.


Once both are done, you'll be shown a summary page with your average download speed, upload speed, and ping time, which is the time it takes, in milliseconds, to send a packet of data from the server to your computer and back. You'll also be provided with a snippet of code that you can use to display your results on your blog or web site, if you're into that sort of thing.

Now, like I said, your connection speed probably fluctuates a lot. If you want to get a more precise idea of your average speed, you could run the speed test several times, at different times of the day and different times of the week. Just remember that no matter how many times you run the test, Speedtest.net will only give you a general idea of your connection's capabilities and isn't indicative of the speeds you'll achieve for all transfers.

Other options

A lot of internet speed tests use Ookla's network and will give you the same results as Speedtest.net, but there are some other options:

  • CNet eschews the flashy visuals, but works just fine.

  • InternetFrog.com compares your connection speed to various internet connection types with a Java-based test.

  • Broadband Reports has several speed-testing tools, including ones for mobile devices.

  • TestMy.net has download, upload, and "dual" speed tests.

If those sites don't satisfy your insatiable need to test your bandwidth, Broadband Reports also has a huge directory of speed-testing services around the world.

About Jordan Running

Blogger since 1999, Jordan Running went pro in 2005 and never looked back. Sometimes programmer, occasional photographer, and serial tinkerer, he decided to to switch to Linux in 2001 but just hasn't quite gotten around to it yet.

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