v2rayF measures latency in two ways:
When the Xray core is available, Test and Test All start a short-lived local SOCKS proxy on port 10818, route traffic through the selected server, and measure HTTP time to a generate_204 endpoint (Google or Cloudflare).
This matches how v2rayN “Real ping” works: the number reflects the full proxy path, not just a TCP handshake to the server IP.
If you are already connected to the server under test, the app reuses the active SOCKS port (10808) instead of starting a second core.
If the core is missing or the proxy test fails, the app falls back to a raw TCP connect to the server address and port. This can be faster but less accurate for TLS/REALITY/WebSocket nodes.
| Display | Meaning |
|---|---|
123 ms |
Successful measurement |
timeout |
No response within 10 seconds |
— |
Test in progress or not run yet |
After Test All, results are saved with your server list.