Your files stay on your device

# HTTP timing probe

Repeated timed GETs against an https URL: TTFB, totals, and Resource Timing phase splits.
Measurehttps URL

https only: browsers block mixed content.
Attempts (1-6)Cache-bust each attempt

Browser egress

The browser fetches the URL you name, once per attempt, and reads its own Resource Timing entry for the phase split. This page leaves your browser only when you press the button; never on load, never in the background. Nothing is sent anywhere else. Google Analytics still measures the visit to this page, and it never receives what you run through this tool.

Wall-clock TTFB and total come from the fetches themselves; DNS/TCP/TLS splits come from Resource Timing. Cross-origin servers without Timing-Allow-Origin withhold them, the sample says so instead of showing zeros as truth.
Paste, drop, or type to begin. Everything stays on this device.

## More network tools

- [Bandwidth calculator](/network/bandwidth)
[All network tools](/network)

---

Canonical HTML: https://nutter.tools/network/http-timing/
Markdown version: https://nutter.tools/network/http-timing/index.md
Plain-text version: https://nutter.tools/network/http-timing/index.txt
Agent index: https://nutter.tools/llms.txt