How do Internet Speed Tests Work?

We all want to know what is the real speed of our Internet connection, what are the limitations on uploading and downloading, if there is a “traffic jam” in the network, etc. So let’s see how the popular speed tests are performed and how these tests work.

What is a speed test?

An Internet connection speed test measures ping and upload and download speeds. The first is a diagnostic utility that checks the status of the network, the connection between our equipment and our Internet Service Provider (ISP).

Measuring upload and download is important because most ISPs promise speeds of “up to” certain Mbps, but they don’t set the minimum. Sometimes the upload and download speeds are even different: it is what we know as asymmetric connections.

How a speed test works

When we perform a speed test from our computer, our location is first determined, to locate the closest test server. Once the server is located, the service that performs the test sends a signal (the ping) to the server and responds by sending another signal back. This round trip is measured in milliseconds.

Once the ping is complete, the download begins. The service opens various connections to the server to download data. All this is to measure, on the one hand, the time it took to download this data and, on the other, the network resources that have been used for this download.

Once the test service verifies that the connections are correct and adequate according to what we have contracted, download more data, measure the amount downloaded in a limited time and the download speed.

Then the load is tested, the data upload. Basically it is the same process, but in reverse: sending data from our computer to the server.

How accurate are these tests?

Although everything we have explained so far seems simple, in reality it is a quite complex process, with several steps to follow and, depending on all those steps, the accuracy of the measurement will be greater or less.

An example. The first thing to do when performing a speed test is, as we have said, find a nearby server to send the ping. This is fine, but not all our connections are always made to nearby servers, so the speed will vary greatly. That is why, also, we will have different results in each measurement: each time a different server is chosen, at a different distance.

Here are some links which will provide you most accurate result:

https://www.speedtest.net/

https://www.testdevelocidad.es/

https://fast.com/

https://openspeedtest.com/Get-widget.php

https://www.spectrum.com/internet/speedtest-only

What to do to correctly measure our Internet speed?

To achieve the best possible result in speed measurements, the first thing we have to do is forget about WiFi: if we really want to know the speed we have, we should use an Ethernet cable connection.

Secondly, we should stop all programs that are accessing the Internet. Of course, we must do the same with all the objects in the house: Smart TV, smart speakers, etc.

One last tip: we will restart the router before running the speed test, so we will clear the navigation cache and we will have an almost pure test.