Runtime logs now show cache reasons
Runtime logs now display detailed cache reasons explaining why requests weren't fresh cache hits, such as time-based or tag-based revalidations. This helps developers debug cache misses and improve cache hit rates across ISR, Partial Prerendering, and functions.
Runtime logs now show a Cache Reason explaining why a request wasn't a fresh cache hit, for example a time-based or tag-based revalidation. Use cache reasons to debug misses and improve your hit rate.
Cache reasons appear for any response the CDN can cache, including ISR, Partial Prerendering, and functions that set a header with directives like . Responses rendered dynamically on every request don't have a cache reason.Cache-Controlstale-while-revalidate
Open the Logs tab and select a request to see the reason alongside its cache status. Each status and reason links to its entry in the reference.Cache Status and Reasons
Cache reason is available in , , and Vercel plugin's :vercel logsvercel metricscdn-caching skill
Learn more about .cache statuses and reasons
Cache status | Possible reasons |
MISS | Cold, Request collapsed, Error |
BYPASS | Draft Mode, Prerender Bypass, Crawler |
STALE | Time-based revalidation, Tag-based invalidation, Revalidation error |
REVALIDATED | Tag-based deletion |
From the CLI
Source: original entry ↗