How Server-Timing works
Add entries for database queries, cache lookups or rendering, and they appear under Timing in Chrome and Firefox dev tools, and in the serverTiming field of the Resource Timing API for real-user monitoring. Cross-origin requests only expose it with Timing-Allow-Origin.
Examples
Server-Timing: db;dur=53.2;desc="Orders query", cache;desc="HIT", total;dur=88Common mistakes
- Timings reveal how your backend works; consider sending them only to logged-in staff or in non-production environments.
Check it
curl -sI https://example.com | grep -i '^server-timing:'Paste a full set of response headers into the HTTP header checker to get every header explained and common mistakes flagged.
Related headers
- Cache-Control: tells browsers, CDNs and proxies whether a response may be stored, by whom, and for how long.
- Age: tells how many seconds a response has spent in a cache (usually a CDN) since it was fetched from the origin.
- Retry-After: tells the client how long to wait before trying again, after 429, 503 or a redirect.
More requests, redirects and more headers
Location , User-Agent , Host , Link , Sec-Fetch-Site , Clear-Site-Data .
Sources
Spotted a mistake? Email hello@devtoolsmith.com and we’ll fix it.
Frequently asked questions
What does the Server-Timing header do?
The Server-Timing response header reports how long the server spent on each step, shown in the browser’s network panel. Add entries for database queries, cache lookups or rendering, and they appear under Timing in Chrome and Firefox dev tools, and in the serverTiming field of the Resource Timing API for real-user monitoring. Cross-origin requests only expose it with Timing-Allow-Origin.
How do I see the Server-Timing header?
Run "curl -sI https://example.com" to print a response’s headers, or open the Network tab in your browser’s dev tools and select the request. Paste the headers into the HTTP header checker on this site to get each one explained.