Server-Timing response headers will pass through to the client
Mirrored from Vercel — AI for archival readability. Support the source by reading on the original site.
Vercel's CDN will begin passing through the Server-Timing response header to the client on August 10, 2026.
Use Server-Timing to report backend metrics like database query time and cache hits. These values appear in the browser's network panel and as PerformanceServerTiming entries through the Performance API.
Server-Timing: db;desc="Database";dur=53,cache;desc="Cache";dur=4.2If you want to keep the current behavior, where the header is stripped from every response, you can add a transform in vercel.json:
"$schema": "https://openapi.vercel.sh/vercel.json",
"routes": [
"src": "/(.*)",
"transforms": [
"type": "response.headers",
"op": "delete",
"target": {
"key": "server-timing"
Learn more about the Performance API and Server Timing.
Discussion (0)
Sign in to join the discussion. Free account, 30 seconds — email code or GitHub.
Sign in →No comments yet. Sign in and be the first to say something.