Why Do Speed Tests Vary Speed Test

Average Why Do Speed Tests Vary Internet Speed

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Speed tests measure your Internet connection's upload and download speeds. If you use an online speed test to see how fast your connection is, you may notice that sometimes one result is faster than another. Why does this happen? There are several things that affect the speed of a speed test

When you see a speed test result for an Internet connection, the number is usually pretty high. For example, if you're testing your download speed from SpeedTest.net at Wired to the Max, your test will likely give results above or near 20 Megabits per second (Mbps). And that's probably faster than the speeds most people get during peak usage times of the day. which might be more like 3-4 Mbps on average based on my own observations and informal surveys I've conducted with friends and colleagues.

Is it possible to get a reliable measure of my internet speed?

The answer is Yes.  But, the only reliable way to know your actual download and upload speeds from your ISP connection, both at peak (afternoons) and off-peak times (night), is through direct testing of your ISP's network by an independent third party.

You have two choices: perform a True Test™ or use Ookla's SpeedTest.  This article compares these tests for speed reliability as well as the fastest measured speeds which can be used in promotional advertising to attract new customers.

How accurate are those numbers?

How Internet speed is usually specified. The two most common ways are by the maximum ("burst") speed that the device or network can handle, and by the average (" sustained ") speed over a period of time.

Speed tests measure one or both of these values, depending on what you're trying to evaluate. For example, if you're measuring your home Internet connection, then you should expect to see numbers for each.

Testing for burst speed:

Most consumers know about testing their "top" (or highest) speeds from websites like SpeedTest.net and TestMy.net. But those tests really only measure your device's capability -- not necessarily how well it'll perform for you in real-world use.

When you perform a speed test, the number returned is based on your device's maximum capability at the time of testing. You could try to make yourself run as fast as possible when you're taking the test, but if those results are not consistent, then they don't really tell you much about your actual performance characteristics.

Sustained speed tests:

For sustained speeds, many consumers simply use Speed Test to estimate their typical connection bandwidths while online. According to this website, "You can expect results that are similar to other tests from locations near you." If there was ever an accurate description of "the wild west," this would be it for Internet speed testing!


For most consumer Internet connections, the average (or sustained) download speed is typically more important than the maximum upload speed. One reason is that most people consume much more data by downloading content from Web sites (e.g., movies, TV shows), rather than uploading their own files to others' servers.