Runtime Cache

After the migration, each project and environment on the Pro plan gets its own Runtime Cache storage quota, 8 times the space of the former team shared pool.

The merged Runtime Cache does not replace CDN cache: the former handles data reuse, the latter handles response reuse.

Runtime Cache provides the direct getCache API in @vercel/functions, usable by frameworks such as SvelteKit and Nuxt.

Runtime Cache's underlying architecture uses a Go API to handle requests, with a Redis cluster behind each Vercel region.

According to Vercel, the Runtime Cache service handles over 440 million reads per hour and moves over 18 TB of data.

Runtime Cache caches are isolated by region; on a miss, the application or framework fetches or computes the value itself and writes it to the local region's cache, and the service does not look up copies across regions.

Runtime Cache uses a tag invalidation mechanism: each cache entry records its tag and write time, and reads check the most recent invalidation timestamp for that tag; if the tag was invalidated after the entry was written, the entry is treated as expired.

Runtime Cache's tag invalidation timestamps are distributed through a global push pipeline, typically reaching other regions within a few hundred milliseconds.

During the circuit breaker's fallback period, just-invalidated data may briefly be treated as fresh, which is the consistency cost.

According to Vercel's data, after enabling the circuit breaker, p99 read latency in the largest region at peak dropped to about one-fifth of the previous level, and the related alerts no longer fire.

In Enterprise projects with frequent evictions, the cache miss rate roughly halved within about a day.

After the merge, Next.js's four APIs — fetch cache, unstable_cache, getCache and 'use cache: remote' — are all served uniformly by Runtime Cache.

Data Cache reads and writes that were previously free will now be billed at Runtime Cache pricing.

Starting October 30, 2026, existing Hobby and Pro teams can opt in to Runtime Cache early from the team's CDN settings, and once they opt in, Runtime Cache pricing takes effect immediately.

Vercel bills caching by read units and write units rather than directly by request count or storage bytes; the unit price of a write unit is about 10 times that of a read unit.

Disabling fetch and unstable_cache caching suits scenarios with low cache hit rates, extremely high data real-time requirements, or cache costs higher than origin costs; but disabling will not stop the migration process, nor will it refund already allocated Runtime Cache quota.

Next.js's fetch cache and unstable_cache will automatically switch to Runtime Cache in all versions without requiring code changes.

Runtime Cache is the name Vercel gave Data Cache after taking it from beta to general availability as a product; underneath it is still built on Vercel's edge network and regionalized storage.

Runtime Cache introduces a quota model isolated by project and environment, along with a dedicated dashboard, billing units and optimization tools.

Runtime Cache rates start at $0.40 per million read units and $4.00 per million write units, and vary by region.