Test your connection’s VoIP quality

How this VoIP speed test works

An internet call (VoIP) cuts your voice into small packets sent every 20 milliseconds. For the call to be clear, those packets must arrive quickly, at a steady pace, and not get lost on the way. This VoIP quality test checks exactly those three things, right from your browser, with nothing to install.

It starts by contacting our calling servers in several regions of the world: an encrypted connection to each one, and a check that UDP, the protocol that carries your voice, can leave your network. It then measures latency, jitter and upload and download speed against the measurement server closest to you.

From those measurements, the tool calculates an estimated quality score out of 5 (the MOS score) and gives advice suited to your result. The whole VoIP test takes about thirty seconds.

Understanding latency, jitter and packet loss

These three measurements decide call quality far more than the headline speed of your internet plan. A very fast fibre connection can give poor calls if it is unstable, and a modest connection can be enough if it is steady.

• Latency (or ping) is the round-trip time between your computer and a server, in milliseconds. Under 150 ms, conversation feels natural; above 300 ms, people start talking over each other.
• Jitter measures how irregular that delay is. If some packets arrive in 20 ms and others in 90 ms, the phone has to put them back in order and your voice sounds robotic or choppy. Benchmark: under 30 ms.
• Packet loss is the share of packets that never arrive. Above 1%, syllables disappear. This test does not measure it (see why below).
• The MOS score (Mean Opinion Score) sums it all up on a scale of 1 to 5, as if listeners were rating the call. Above 4, quality is considered good; with the G.711 codec, the model tops out around 4.4.

What internet speed do you need for VoIP?

Less than you might think. A VoIP call uses about 100 kbps in each direction with the G.711 codec, and less with Opus. An upload speed of 1 Mbps is therefore plenty, as long as nothing else is saturating it.

The direction that matters most is upload, the one that sends your voice. It is often the weak spot of DSL and 4G connections. This test keeps the weaker of the two directions and leaves headroom for the rest of your activity.

• 1 call: about 0.1 Mbps up and down.
• Test benchmark: at least 0.8 Mbps in the weaker direction, to keep comfortable headroom.
• Beyond that, more speed does not improve your voice: stability (latency and jitter) is what makes the difference.

How to improve your VoIP call quality

Most audio problems come from the local network, not the carrier. Here are the fixes, from most to least effective.

• Plug in with Ethernet: a cable removes most of the jitter caused by Wi-Fi.
• On Wi-Fi, prefer the 5 GHz band and move closer to the router; avoid cheap repeaters.
• Turn off your VPN during calls, or have voice traffic excluded from the tunnel.
• Stop large transfers: file syncing, updates, video streaming.
• Ask your IT team to allow outbound UDP and your VoIP provider’s domains.
• Use a wired headset with a microphone rather than your computer’s speakers.
• Keep a backup: your phone’s 4G or 5G hotspot.