Impello and Docker Sandboxes

If you are on Docker's $250 credit

Docker's promotion gives new Docker Agentic Platform accounts that sign up by October 31, 2026, 11:59 PM PT a one-time $250 compute credit. The credit expires 6 months after you redeem it. After that, a Small sandbox runs at Docker's list rate.

If you take the credit, know what the hour costs once it is spent. The rest of this page works that out at the same size on both.

Is Impello the right fit?

Impello runs short- and medium-lived Linux sandboxes for AI agents, code execution, dev environments and CI-style jobs, booted from a template built from your Dockerfile or base image.

What it does not do:

• a sandbox runs for at most 1 hour on the trial, 12 hours ($20 plan) or 24 hours ($100 and $500 plans); at its deadline it is killed and its disk goes with it, unless you set lifecycle: { onTimeout: 'pause' }
• there is no SLA, no status page and no support channel
• sandboxes run in the EU only (Germany and Finland)

Price, side by side

From Docker's Sandboxes promotion and Impello limits and pricing, both read on 25 October 2026. Docker's page does not list storage, egress or paused-sandbox charges, so they are not in this table.

The math: one 2 vCPU / 4 GB sandbox for one hour

• Impello: 2 vCPU × $0.0000025 × 3,600 s = $0.018, RAM not billed
• Docker Sandboxes: the Small size's hourly list rate on Docker's promotion page
• Docker Small ÷ Impello = about 7.8×

In our benchmark of nine providers at this size, the three fastest boxes finished the same CI run within 12% of each other: speed is a tie within 12%, price is the gap. Docker Sandboxes was not in that run, so we make no speed claim about it.

Both bill while a sandbox runs, idle or not. On Impello, pause a sandbox while it waits and it costs $0.

What Docker's users ask

On Docker's forum, a team evaluating sandboxes for AI agents asked whether Docker Sandboxes needs a paid subscription for business use, and found the pricing unclear. No Docker staff answered in the thread; the answer was passed on second-hand.

Impello's whole price is on one page: limits and pricing. Every plan meters compute at the same rate and returns its price as credit.

What moves over

• Your image. Build a template from Ubuntu or Debian with aptInstall and runCmd, at the size you need (cpuCount, memoryMB). Build a template
• Environment variables. Pass them with envs on Sandbox.create, from your own secret store. Impello has no secrets store of its own.
• Long-lived work. A sandbox lives 5 minutes unless you set timeoutMs, up to your plan's maximum. Pause and resume instead of keeping a box on; a paused sandbox costs nothing and is kept 14 days. Timeouts
• Public ports. Every listening port gets a public host by default; turn it off with network: { allowPublicTraffic: false }. Network and public URLs

FAQ

Is Impello less per hour for every workload?

At the same size and the same running time, yes, by the ratio above. But Docker's $250 credit covers a lot of hours while it lasts, and a workload that fits inside it costs you nothing there until the credit runs out or expires.

Do I need a card?

Yes. The 7-day trial needs a card and includes $5 of credit; it allows 2 sandboxes at once and 1 hour per sandbox.

Can I run my production app here?

We don't recommend it. Impello has no SLA, and a sandbox runs for at most 12 or 24 hours.