VPN Speed Test

The test measures one path, now: this browser to one server. It sends 12 pings and reports the minimum, median, 90th percentile and mean. A full run then downloads 256 KB, 1 MB, 4 MB and 8 MB and uploads 1 MB and 4 MB of random bytes. The first transfer in each direction is discarded, because it includes the handshake and TCP slow start, and the larger steps stop once one transfer takes longer than 12 seconds.

While the 4 MB and 8 MB downloads run, the page keeps pinging the server with a 200 ms pause between pings. Those pings are the under load figures. Choose pwnsy in Helsinki for a long path, or Cloudflare's nearest edge for your local ceiling; with Cloudflare the page also reads the edge location code and whether WARP is on.

• Median latency is the middle of the 12 idle pings. Geography dominates it, so compare tunnel off and on against the same server.
• Jitter is the mean change between consecutive pings. Above 12 ms reads amber and above 30 ms red; a median above 250 ms also reads amber.
• Under load is the median ping during the download minus the idle median. That added delay is bufferbloat: up to 30 ms good, up to 100 ms fair, above that poor.
• Download and upload are the best rate after the warm-up transfer. 25 Mbps or more reads green, 6 Mbps or more amber, below that red.
• Compare runs shows each run as a percentage change from the baseline you pick. Green is better.

Healthy latency (120 ms or less) with download under 6 Mbps usually means full-size packets no longer fit once the tunnel adds headers, which the MTU finder pins down.