Quelle est la vitesse de ma connexion ?
C'est la seule mesure du site qui ne peut pas venir de nos propres données : elle doit transférer de vrais octets au débit maximal de votre ligne. Cette partie est assurée par OpenSpeedTest, sur son réseau — tant que vous n'avez pas lancé le test, rien n'est chargé et rien ne leur parvient.
Lancer le test charge le widget OpenSpeedTest. À partir de là, la mesure a lieu entre votre navigateur et leurs serveurs, qui voient donc votre adresse et le transfert — rien d'autre sur ce site ne le fait. Tant que vous ne cliquez pas, aucune requête ne leur est envoyée.
Où le test s'exécute
Un test de débit doit saturer votre ligne pendant plusieurs secondes, ce qui représente des téraoctets pour quelques milliers de tests. L'assumer nous-mêmes reviendrait à dépenser en bande passante ce qui garde le reste du site gratuit — et un serveur saturé finit par se mesurer lui-même plutôt que vous. OpenSpeedTest est libre, gratuit y compris pour un usage commercial, et exploite un réseau conçu pour cela : le chiffre est le leur, et il est meilleur. Tout le reste ici reste répondu à partir de données que nous compilons nous-mêmes.
A speed test moves data between your browser and a server and times it. The number it produces is the capacity of the path between those two points at that moment — not a property of your line, and not a promise about any other destination. The measurement here is run by OpenSpeedTest, on their network rather than ours.
What the three numbers mean
Download is how fast data reaches you, and it is the number that decides whether video buffers. Upload is how fast it leaves, which matters for video calls, backups and sending large files; on most cable and DSL lines it is a fraction of the download figure by design. Latency is how long a round trip takes, and it is what makes a connection feel quick or sluggish — for calls and games it matters far more than raw speed. Jitter is how much that round trip varies, and a high figure is what turns a call choppy even when the speed looks fine.
Why our number can differ from your provider's
A provider quotes the capacity of the line into your home. This test measures the whole path from your browser to the test server: your Wi-Fi, your router, everything else on the line, your provider's network, and the route out to the nearest OpenSpeedTest node. A result below the advertised figure usually means a bottleneck somewhere along that path rather than a fault on the line, which is why a wired test on an otherwise idle connection is the one worth comparing.
Why the test is not ours
Every other answer on this site is read from data we compile, on our own hardware, with nothing about your visit leaving it. A speed test cannot work that way: it has to saturate your line for several seconds, which is terabytes of traffic for every few thousand tests, and an origin busy serving that measures its own congestion as much as your connection. So this one page hands the measurement to OpenSpeedTest — open source, free for commercial use, and running a network built for it. The widget is not loaded until you press start, so their servers see nothing about a visitor who only reads the page.
Questions fréquentes
Why is my speed lower than what I pay for?
Most often Wi-Fi, an older router, or something else on the line using it at the same time. Beyond your home, the path to any given server can be congested even when your line is not. Test over a cable with everything else idle, and compare a few servers before concluding the line is at fault.
Does a VPN slow the test down?
Almost always, yes. The traffic takes a detour through the VPN's exit server and is encrypted on the way, so both the speed and the latency you see belong to that path rather than to your own connection.
What is a good latency?
Under 30 ms is excellent for anything interactive, and under 60 ms is comfortable. Satellite links run into the hundreds and mobile networks vary with signal. Jitter above roughly 30 ms is what makes calls break up, even on a fast line.
Who sees my address when I run the test?
OpenSpeedTest does, once you start it — the bytes have to go somewhere, and they go to their servers. We do not record the result, do not receive it, and do not associate anything with your address; nothing is loaded from them at all until you press start. Reading this page without starting the test contacts no one but us.