# Runtime logs now show cache reasons

DevFeed: [Runtime logs now show cache reasons](<https://devfeed.tech/articles/runtime-logs-now-show-cache-reasons-1079.md>)

Original publisher: [Read original article](<https://vercel.com/changelog/runtime-logs-now-show-cache-reasons>)

Author: Shina Patel

Published: 2026-07-17T01:00:00Z

Content type: release

Language: en

Sources: [Vercel News](<https://devfeed.tech/sources/vercel-news.md>)

Topics: [telemetry](<https://devfeed.tech/topics/telemetry.md>), [Grafana](<https://devfeed.tech/topics/grafana.md>)

Tags: [cache](<https://devfeed.tech/tags/cache.md>), [cdn](<https://devfeed.tech/tags/cdn.md>), [cli](<https://devfeed.tech/tags/cli.md>), [debug](<https://devfeed.tech/tags/debug.md>), [logs](<https://devfeed.tech/tags/logs.md>), [metrics](<https://devfeed.tech/tags/metrics.md>), [vercel](<https://devfeed.tech/tags/vercel.md>)

## AI overview

Vercel runtime logs now display cache reasons for cacheable CDN responses, helping developers diagnose cache misses and improve hit rates. The reason is available in the Logs tab and through selected CLI commands.

## Source excerpt

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 Cache-Control header with directives like stale-while-revalidate. Responses rendered dynamically on every request don't have a cache reason. 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 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 Cache Status and Reasons reference. From the CLI Cache reason is available in vercel logs, vercel metrics, and Vercel plugin's cdn-caching skill: Learn more about cache statuses and reasons. Read more