Vercel CDN no longer caches responses with Vary: Cookie
Vercel CDN has changed its caching behavior to exclude responses with the Vary: Cookie header, as cookies often contain visitor-specific values that create cache entries with poor reuse rates. Users can identify affected responses via the x-vercel-cache header showing MISS and vary_key_denied:cookie in Runtime Logs, and can restore caching by removing Cookie from the Vary header or using Cache-Control: private if the response depends on cookies.
Vercel CDN no longer caches origin responses when includes . VaryCookie
tells a cache which request headers may change the response. Because cookies often contain visitor-specific values, varying by can create many cache entries that are rarely reused. The response is still served normally but isn't stored for future requests.VaryCookie
You can identify these responses by checking the header and . The header is set to , and Logs show as the cache reason.x-vercel-cacheMISSvary_key_denied:cookieRuntime Logs
If Logs show for a route you expect to be cached, check the header returned by your origin:vary_key_denied:cookieVary
Caching behavior for other supported headers is unchanged.Vary
Learn more about and the .high-cardinality headers cache reasonvary_key_denied
If the response is the same regardless of cookies, remove from . Vercel CDN can then cache it if it meets the other caching requirements.
CookieVaryIf the response depends on cookies, keep in and use to prevent personalized responses from being stored in the shared CDN cache.
CookieVaryCache-Control: private
Source: original entry ↗
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