Modal Sandboxes vs Vercel Sandbox

Modal Sandboxes

GPU sandboxes at the same per-second rates as the rest of Modal. No REST API, and the JavaScript and Go SDKs are beta.

Vercel Sandbox

Active CPU billing, so waiting on model responses costs only memory. Tied to a Vercel team and project even when called from elsewhere, and access tokens reach the whole team.

Modal Sandboxes

1. Pass timeout= when you create a sandbox. The default lifetime is 5 minutes
2. Set block_network=True or a cidr_allowlist for untrusted code
3. Give a sandbox a name so a retried create raises AlreadyExistsError instead of starting a second one
4. Snapshot the filesystem before the 24-hour limit and start a fresh sandbox from it
5. Catch ResourceExhaustedError from Sandbox.create() on SDK 1.6.0 and later

Vercel Sandbox

1. Call sandbox.stop() when the task is done. Memory bills until the session ends
2. Use Sandbox.getOrCreate with a name so retries land in the same sandbox
3. Set networkPolicy to deny-all for untrusted code. The default is allow-all
4. Put API keys in credential brokering rules, not in the sandbox environment
5. Pass persistent: false for one-off runs so no snapshot is stored or billed