# Runtime logs now show cache reasons By Steven Van · 2026-07-17 Vercel's runtime logs now explain why a request missed the cache, viewable per request or via the CLI and metrics API. [Vercel]()'s runtime logs now include a Cache Reason alongside each request's cache status, explaining why a response wasn't a fresh hit, for example a time-based or tag-based revalidation. 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 that render dynamically on every request don't get a reason. Possible reasons are grouped by status: **MISS** can be Cold, Request collapsed, or Error; **BYPASS** can be Draft Mode, Prerender Bypass, or Crawler; **STALE** can be Time-based revalidation, Tag-based invalidation, or Revalidation error; and **REVALIDATED** shows Tag-based deletion. Reasons are visible in the Logs tab by selecting a request, and each links to its entry in the [Cache Status and Reasons]() reference. They're also available from the CLI through vercel logs, vercel metrics (grouped by cache\_reason), and the Vercel plugin's cdn-caching skill. [![]()]() ![Vercel]() Vercel The platform for frontend developers — deploy, preview, and scale web apps and AI agents with zero config. [View Vercel →]() Sources [Original source]() [Read Runtime logs now show cache reasons on Creators Toolbox]() --- Canonical source: https://creatorstoolbox.com/blog/vercel-runtime-logs-now-show-cache-reasons