How this packet loss test works
Most of a speed test uses ordinary web requests (TCP), which automatically resend anything that goes missing. That hides packet loss. To see it, this test uses WebRTC to open a UDP connection through a TURN relay on Cloudflare’s network, the same kind of connection video calls use.
Your browser sends 1,000 numbered packets in small batches through the relay and back to itself, waits a few seconds for stragglers, and reports the share that never returned. The relay is accessed with short-lived credentials issued for each test.
Reading your result
| Packet loss | What it usually means |
|---|---|
| 0% | No loss during the test. Ideal. |
| Under 1% | Usually unnoticeable for browsing and streaming. Calls and games may glitch occasionally. |
| 1–2.5% | Noticeable in calls (dropped syllables) and games (rubber-banding). |
| Over 2.5% | A real problem. Real-time apps will struggle and downloads will slow. |
Microsoft’s guidance for Teams calls targets packet loss under 1% over any 15-second period. A single test is a snapshot; loss that comes and goes may not show up every time. If you suspect a problem, run several tests over a day.
Where packet loss comes from
- WiFi: weak signal, interference and congestion are the most common sources in homes.
- Overloaded equipment: an old router or one running too hot can drop packets under load.
- Faulty cables and connectors on Ethernet, coax or phone lines.
- Your provider’s network: line faults or congestion upstream.
Testing wired, then on WiFi, then at different times, narrows it down. The step-by-step method is in how to fix packet loss.