# Slow internet: how to measure your speed and find out who is to blame > Measure your connection speed with neutral tools, find out whether the slowdown comes from your home Wi-Fi or from the line and, if the line is below what was promised, get the Ne.Me.Sys. certificate that counts for complaints and contract termination. Source: https://simplebuild.it/tutorial/misurare-velocita-internet Author: SimpleBuild, Build simple. Deliver value. Category: Internet and Wi-Fi Procedure verified on: 2026-09-29 To find out how fast your line really is, connect a computer to the modem with a network cable, close anything that is downloading and run a speed test, that is, a speed measurement, with a neutral tool: for example the one from **MisuraInternet**, the project of AGCOM, Italy's communications regulator. Repeat the test at different times. If it is fine over the cable and not over Wi-Fi, the problem is in your home. If it is slow over the cable too, the problem is the line, and to challenge it with your provider you need the free **Ne.Me.Sys.** certificate. ## Before you start - **Find your contract** or the offer summary. You need the promised speed and, above all, the minimum speed the provider states: that is the figure to compare your measurement with. - **Get a network cable**, if you can, and a computer with the right port. Measuring over a cable takes Wi-Fi out of the picture and tells you what the line is like. - **Stop whoever is using the internet at home**: TVs streaming, updates, cloud backups, video calls. If other devices are downloading, the network is busy and the measurement comes out lower. ## What the numbers mean - **Download**: how fast you receive data (pages, videos, files). It is measured in Mbit/s. - **Upload**: how fast you send data (photos to the cloud, attachments, your picture in video calls). - **Ping** or **latency**: the round-trip time of a small message to the test server, in milliseconds. The lower it is, the more "responsive" the connection. - **Jitter**: how much the ping changes from one test to the next. If it is high, video calls and online games can stutter. ## Measure with MisuraInternet (AGCOM) MisuraInternet is the platform of the Italian Communications Authority (AGCOM), built with Fondazione Ugo Bordoni. It is free and does not belong to any provider. 1. Open [misurainternet.it](https://www.misurainternet.it) and go to the **speed test online** (the online speed test). 2. Start the test and wait for it to finish, without using the computer in the meantime. 3. Write down download, upload, ping and jitter, with date and time. The online speed test sends and receives a random file to measure download and upload, and sends 10 pings to the server to measure latency and jitter. It is an instant reading: useful for understanding, **not valid** for a complaint. ## Other neutral tools - **Speedtest by Ookla**: use it from [speedtest.net](https://www.speedtest.net) or from the apps for Windows, macOS, iPhone and Android. Among other things, it measures speed and latency. - **M-Lab Speed Test** (Measurement Lab): from [speed.measurementlab.net](https://speed.measurementlab.net) it measures download, upload and latency. Before starting, it asks you to accept a data policy that includes the retention and **publication of your IP address**: if you are not comfortable with that, use another tool. Different tools use different servers, so the numbers never match exactly. Compare measurements taken with the same tool. ## How to take a measurement that really helps 1. **Cable first.** Connect the computer to the modem with the network cable and turn off the computer's Wi-Fi. Take three measurements a few minutes apart. ![Drawing of a laptop connected to the modem with a network cable, with the laptop Wi-Fi turned off](https://simplebuild.it/assets/img/tutorial/misurare-velocita-internet-cavo-en.svg) 2. **Then Wi-Fi**, from the same computer, first close to the router and then in the room where the internet seems slow. 3. **At different times.** Repeat in the morning, the afternoon and the evening. When many devices use the network, speed can drop: a single measurement is just a snapshot of that moment. 4. **Don't rely on the phone alone.** Some devices, such as phones, can't reach the speeds of a computer even on a perfect line. ## Who is to blame? - **Fine over the cable, fine over Wi-Fi near the router, slow farther away**: the line is fine, the Wi-Fi signal doesn't reach well. See [Wi-Fi that doesn't reach the whole house](https://simplebuild.it/tutorial/wifi-che-non-arriva-in-tutta-casa). - **Fine over the cable, slow over Wi-Fi even near the router**: the problem is the router or the device. Try restarting the router and check for firmware updates: see [how to log in to your router](https://simplebuild.it/tutorial/entrare-nel-router). - **Only one device is slow**: the problem is that device (updates in progress, programs downloading, an old network card). - **Slow over the cable too, at any time**: the problem is the line. This is where Ne.Me.Sys. comes in. - **No connection at all**: that is a different problem, see [Wi-Fi connected but no internet](https://simplebuild.it/tutorial/wifi-connesso-senza-internet). ## If the line is slower than the contract: Ne.Me.Sys. **Ne.Me.Sys.** is MisuraInternet's free program that measures your fixed-line connection and issues a certificate that counts as evidence, usable for a complaint and for terminating the contract. 1. Register on the MisuraInternet website and download the program: it is available for the main computer operating systems. 2. During the measurement the computer must stay **on** and **connected to the modem with the cable**, with Wi-Fi between computer and modem turned off. 3. Turn off the other computers and, if you have them, the internet TV and the phone that runs over the internet. Use the computer as little as possible. 4. A measurement session lasts at most **3 days** from the first completed measurement. At the end you get the certificate. If the certificate shows worse values than those stated by the provider: 1. File a **complaint** with your provider, attaching the certificate, **within 30 days** of the date shown on the certificate. 2. The provider has **30 days** from receiving the complaint to bring the service back to the guaranteed levels. 3. After its intervention, and in any case no sooner than 30 days after the first certificate, take a **second measurement** with Ne.Me.Sys. Each later measurement must be taken at least 30 days after the previous one and no more than 90. 4. If the second certificate is also worse than what the provider stated, you have the right to **terminate the contract without penalties**, for the part covering internet access. ## If it still doesn't work - **The test won't start or freezes.** Briefly turn off VPNs and ad blockers, try another browser, or try another of the three tools. - **Speed collapses only at certain times.** Keep a small log of your measurements with date and time: it is useful to you and to whoever helps you. - **You don't have a computer with a cable port.** Many recent laptops don't: there are USB adapters for wired networking. - **You have measured everything and don't understand the result**, or the line is fine but everything at home is slow: a technician can take measurements in the right places in the house and tell you where the bottleneck is, before you switch providers or buy new equipment. ## Frequently asked questions ### Does a speed test on my phone count? It gives you a rough idea, but a phone often can't reach the speeds of a computer, and it goes through Wi-Fi. To see what the line is really like, test from a computer connected to the modem with a cable. ### Can I file a complaint with the result of an online speed test? No. Even the MisuraInternet online speed test gives an instant reading, not valid for a complaint or for terminating the contract. For that you need the Ne.Me.Sys. certificate. ### Why is the internet slower in the evening? When many people use the network at the same time, speed can drop. That is why it is worth repeating the tests at different times and comparing them. ## Sources - [MisuraInternet, online speed test (AGCOM and Fondazione Ugo Bordoni) (in Italian)](https://misurainternet.it/misura-speedtest/) - [MisuraInternet, the certified measurement with Ne.Me.Sys. (in Italian)](https://misurainternet.it/info_nemesys/) - [MisuraInternet, how to file a complaint (in Italian)](https://misurainternet.it/reclamo/) - [Network quality projects (AGCOM) (in Italian)](https://www.agcom.it/competenze/consumatori/interventi-regolamentari-sulla-qualita-dei-servizi-attuazione-del-nuovo-0/progetti-qualit%C3%A0-reti) - [About Speedtest (Ookla)](https://www.speedtest.net/about) - [Speed Test by Measurement Lab (M-Lab)](https://speed.measurementlab.net/) - [Internet speed test guide (Google Nest Help)](https://support.google.com/googlenest/answer/6246634?hl=en)