Server-Timing response headers will pass through to the client
By Steven Van ·
On August 10, 2026, Vercel's CDN will stop stripping the Server-Timing response header and begin passing it through to the client.
From 10 August 2026, Vercel's CDN will stop stripping the Server-Timing response header and will pass it through to the client instead. Backend metrics such as database query time and cache hits reported via Server-Timing will now show up in the browser's network panel and as PerformanceServerTiming entries through the Performance API.
Sites that want to keep the current behaviour, where the header is stripped from every response, can add a response.headers delete transform for the server-timing key in vercel.json. Read the announcement for the full config example.
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