# Speed test

> A quick check of how fast your internet connection really is right now.

- Level: Basic
- Topics: Networks
- URL: https://tidbit.legios.com.ar/speed-test/
- In Spanish: [Test de velocidad](https://tidbit.legios.com.ar/es/speed-test/)

A **speed test** is a website or app that measures your internet connection in a few seconds. It connects to a nearby test server and reports three numbers: **download** speed, how fast data reaches you; **upload** speed, how fast you can send it; and **ping**, how long a small message takes to go and come back. Speeds are shown in megabits per second (Mbps), ping in milliseconds (ms).

To measure download, it pulls as much data as it can for a few seconds over several connections at once and divides by the time; upload is the same in reverse. Popular ones are Ookla's Speedtest, Netflix's Fast.com and M-Lab's open test, which also publishes its results for researchers.

The result is a snapshot of the whole path, not just of the plan you pay your ISP for. A weak Wi-Fi signal, an old router, a busy evening in the neighborhood or a test server far away can all pull the number down. To check what your plan delivers, test with a cable, close other downloads and repeat at different times of day.

## An analogy

Like timing how long it takes to fill a bucket from your tap. It tells you what the water does at that moment, but a half-closed valve in your own house can make the city's pipes look worse than they are.

## Keep in mind

- It reports download, upload (both in Mbps) and ping (in ms).
- Most home plans give much more download than upload.
- Wi-Fi, other devices and server distance all affect the result.
- For a fair reading, use a cable and test several times.

## Go deeper

- [Fast.com, Netflix's speed test](https://fast.com/)
- [M-Lab open speed test](https://speed.measurementlab.net/)
- [Speedtest.net on Wikipedia](https://en.wikipedia.org/wiki/Speedtest.net)

## Related terms

- [Website](https://tidbit.legios.com.ar/website/): A set of web pages under one address, stored on a server and opened in a browser.
- [Internet](https://tidbit.legios.com.ar/internet/): A worldwide network of networks that lets any connected device reach any other.
- [Server](https://tidbit.legios.com.ar/server/): A computer whose job is to answer requests from other computers, all day, every day.
- [Ping](https://tidbit.legios.com.ar/ping/): A tiny "are you there?" message that tests a connection and times the reply.
- [Netflix](https://tidbit.legios.com.ar/netflix/): A streaming service, and the engineering it built to deliver video to the whole world.
- [ISP](https://tidbit.legios.com.ar/isp/): The company you pay to connect your home or phone to the internet.
- [Wi-Fi](https://tidbit.legios.com.ar/wi-fi/): Networking over radio waves: the internet without the cable, within a few rooms.
- [Router](https://tidbit.legios.com.ar/router/): The box that connects your devices to each other and to the internet.