How do internet speed tests work?

Speed ​​tests are a quick way to see how fast the Internet is. ISPs promise up to a certain speed in optimal conditions, but a speed test will confirm how fast or slow your connection is.

What is an internet speed test?

An internet speed test is the best way to get an idea of ​​how fast your connection is right now. The service you connect to often limits your upload and download speeds based on the plan you chose, local congestion, the acceleration rules you have, etc.

The problem is that the promises made by your Internet Service Provider (ISP) almost always include the phrase, "up to". This gives the ISP room to maneuver, if it promised you "up to 30 Mbps." And you always get only 28 Mbps, so the company can say that it has fulfilled its promise. But if you see 10 Mbps, then you are not getting what you pay for, and it is time to call your ISP.

A speed test measures your ping and upload and download speeds. Measuring these last two items is essential because most ISPs make separate promises for upload and download speeds.

In general, the download speed occupies a prominent place, but if you delve into the details, the ISP generally specifies a slower loading speed for each level. For example, our local ISP offers a plan with a download speed of 500 Mbps, but a upload speed of 125 Mbps.

How a speed test works

When you start a speed test, several things happen. First, the client determines your location and the test server closest to you; This part is important. Some versions, such as Ookla, have an option to change the server.

With the test server in place, the speed test sends a simple signal (a ping) to the server and it responds. The test measures that round trip in milliseconds.

Once the ping is complete, the download test begins. The client opens multiple connections to the server and tries to download a small piece of data. At this point, two things are measured: how long it took to capture the data fragment and how much of the resources in your network it used.

If the client detects that you have space to spare, open more connections to the server and download more data. The general idea is to tax your internet connection and see how much you can do simultaneously.

Imagine your internet service as a highway with a speed limit. Opening additional connections is like adding more lanes to the road. The speed limit has not changed, but more cars can pass through the same space at a faster pace.

Therefore, the 50th car will arrive earlier using a four-lane highway than in a two-lane car.

Once the client determines that he has the correct connections to test your internet service, download additional pieces of data, measure the amount downloaded in the allotted time and present a download speed.

The following is the load test. It is essentially the same process as the discharge test, but vice versa. Instead of extracting data from the server to your PC, the client loads the data from your PC to the server.

Are speed tests accurate?

Speed ​​tests sound simple, but it is much harder than it seems to measure how quickly your connection is accurate.

Consider the first step in the process: choose a test server. Often, the nearest server can be incredibly close, perhaps even in the same city.

That proximity is an optimal situation, so the data does not have to travel so far. Companies know that proximity makes a difference, and that is why some, such as Netflix, use a content delivery network to bring data closer to your connection.

But all the internet is not near you. Much is in distant computers, sometimes throughout the country or in another country. So, while your speed test can show incredibly fast transmissions, downloading a program may be very slow if the server that hosts the data is too far away.

In that scenario, the results may reflect faster performance than their use in the real world. The difference in server locations is the reason why you are likely to see different speed results when trying different tests, such as Ookla, Netflix or Google.

Internet speed tests by ISP are not reliable

However, you probably should not rely on a speed test generated by the ISP. Your tests are optimized for ideal conditions, using servers close to you, which are often maintained on the same ISP network from which you perform the tests.

That means you'll get a faster result than you could get with a Netflix or Google speed test. It's fine if you just want to show off how good your ISP is, but it's bad to get an idea of ​​your real-world speeds.

In step two of the test process, the client tries to open additional connections and maximize the use of your network. If your network is already taxing, then the speed test cannot make the most of your resources.

If you try Netflix streaming or download a great update, for example, your results will probably be lower than the tests without running them.

How you are connected and what devices you are testing also affect the results. A computer connected to Ethernet should have a faster speed result than a tablet connected to Wi-Fi because, in general, Wi-Fi is slower than Ethernet. The results may vary on different devices, even if they are using the same connection.

How to get the most accurate results

Obtaining accurate test results depends on what you intend to measure. Do you want to see if your ISP is really providing the speeds it promised? Then, look for the optimal conditions.

Use a device connected to Ethernet, choose the closest test server and stop everything that may be taxing the internet connection, such as a streaming service.

You may even want to restart your router before running a speed test. If your router has a built-in speed test, use it instead of a browser test. In doing so, some of the rings through which the process must pass are eliminated.

However, if you want results closer to real-world performance, use a browser or an application test. Skipping the router test should allow you to choose a more remote server. If you regularly have one or two audio or video transmissions, close them before starting the internet speed test.

Ultimately, no matter what steps you take or how you measure, you will not get a perfectly accurate result. However, you can get a result good enough to satisfy your curiosity or verify the speeds promised by your ISP.