Vercel Sandbox snapshot creation is now up to 10x faster

Vercel announced on 9 November that Sandbox snapshot creation is up to ten times faster, with median creation time dropping from 4.4 seconds to under 0.4. Snapshot restore improved too, from 500ms to 250ms at p50.

The speedup comes from a rewrite of the underlying Vercel Hive Snapshot format: snapshots can now reuse existing frames instead of writing everything fresh, and better indexing lets more reads and writes happen in parallel, including restoring base image data alongside user data at the same time. It applies automatically to every new snapshot on persistent sandboxes, the default mode, which snapshot whenever a session stops and resume from the latest one. No code or config change is needed.

const sandbox = await Sandbox.create({ runtime: 'node22' })
// snapshots now write and restore on the faster VHS format automatically

Why it matters: anyone running coding agents or CI jobs on Vercel Sandbox pauses and resumes constantly, and every pause used to cost over four seconds just to snapshot. Cutting that to under half a second makes stop-start sandbox usage, the pattern most agent frameworks rely on, noticeably cheaper to run at scale.

The caveat: existing snapshots keep the old format, so the gain only applies going forward.