Takes about 20 seconds
Settings
Server: the nearest Cloudflare data centre, chosen automatically. Load: speed.cloudflare.com.
What this test can and cannot measure: a web page cannot see single packets. Web requests travel over TCP or QUIC, which quietly resend lost packets, so real packet loss usually shows up here as delay rather than as a missing answer. A true packet loss measurement needs a tool that sends raw UDP or ICMP packets, which browsers do not allow. What we count honestly is lost requests: of all the small round trips sent during the test (one every 0.2 seconds, on a quiet line and during a download and an upload), how many failed or took longer than 2 seconds. Zero lost requests does not prove zero packet loss; many lost requests on a wired device is a clear warning sign. Full method.
What packet loss means
Everything you send online is split into small pieces called packets. Packet loss is the share of those packets that never reach their destination. The IETF defines how to measure it in RFC 7680 (one-way loss) and RFC 6673 (round-trip loss). Downloads quietly resend lost packets, so you may never notice; live calls and games can't wait, so you hear gaps or see characters jump.
What causes packet loss
- Weak or crowded Wi‑Fi, one of the most common causes at home.
- Damaged or loose cables and old connectors.
- Overloaded equipment: a router or modem whose queue overflows drops packets.
- Problems on your provider's line, such as signal issues on cable or DSL.
Some loss is normal on a busy internet: TCP uses dropped packets as a signal to slow down. Steady, noticeable loss on a quiet, wired connection is not normal.
How to fix packet loss
- Repeat the test on a wired device to rule out Wi‑Fi.
- Restart the modem and router, and swap the network cable.
- Update router firmware.
- If loss continues on a cable, contact your provider and share your results with times and dates.
If the problem is lag rather than lost data, see How to fix bufferbloat.
What’s good? Our colour guide
| Lost requests | Range |
|---|---|
| Good | 0 lost requests |
| OK | 1–2 lost requests |
| High | 3 or more lost requests |
These are the labels this test uses, as a rough guide, not an official standard.
Other tests
FAQ
How much packet loss is acceptable?
Ideally none on a wired connection. Even small, steady loss can be heard in voice calls.
Can packet loss cause high ping?
Indirectly. Lost packets are resent, which delays the data that depended on them. Check both with the ping test.
Does a VPN fix packet loss?
Usually not, because the loss most often happens on your own Wi‑Fi or line before the VPN.