Vercel Sandbox starts up to 4x faster outside its primary region

Vercel sped up Sandbox cold starts by up to 4x outside its primary iad1 region using regional caching, cutting Seoul startup time from about 3.5 seconds to about 1.05 seconds.

Vercel announced on November 13, 2026 that its Vercel Sandbox product, used to spin up ephemeral sandboxes for AI coding agents, now starts up to 4 times faster outside its primary iad1 (Washington D.C.) region on cache hits, according to the Vercel Sandbox changelog post.

What changed

Startup is up to 4x faster outside the iad1 (Washington D.C.) region on cache hits
The speedup comes from regional caching of image data, which avoids round trips to iad1 origin storage
Both managed and custom images backed by the Vercel Container Registry are supported, including snapshots
In Paris, benchmark startup time fell by about 75 percent
In Seoul, benchmark startup time fell from about 3.5 seconds to about 1.05 seconds
Regions located closer to origin storage see smaller gains

What it means for builders

Faster sandbox cold starts directly speed up AI coding agents, including Vercel's own v0, that spin up ephemeral sandboxes for every task or preview. For builders running agents from regions farther from Washington D.C., this caching change means noticeably less waiting before a sandbox is ready to run a task or render a preview, while regions located closer to the origin storage will see a smaller improvement since they were already closer to the cached data.

Sources

Vercel Sandbox starts up to 4x faster (Vercel, November 13, 2026, official)

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