Self-hosted Firecracker

Self-hosted Firecracker — The baseline: Firecracker on your own metal, plus every hard part you now own. Firecracker is the microVM monitor underneath most of this roster, and running it yourself on bare metal is the honest baseline every vendor should be measured against. You get 125 ms guest boots, total network control and compute at cost. You also get to build snapshotting, pool warming, image distribution, multi-tenant scheduling, quota enforcement and an API — which is why most of the companies on this page exist. Founded 2018. Open source under Apache-2.0. We carry it as the do-it-yourself baseline, not as a vendor.

We track it in 1 comparison — Sandbox providers — so every claim below is a cell in a table you can open and check rather than an impression. Across those rosters it sits against 19 other tools, and what follows is where it visibly separates from them.

Where it wins.

• Cold start — 200 ms, 3rd of 16.
• Price / hour — $0.03 /hr, the best figure of the 9 here.
• Concurrent limit — 1,000 sandboxes, tied for best across 2 of 13 tools.
• Sydney region — Yes, which only 3 of 16 tools here manage.
• GitHub stars — 27,000, the best figure of the 3 here.

Each of those is ranked against the whole roster on its category page, not against a hand-picked subset, so a first place here means first of everything we list.

Where it gives ground.

• Streaming output — No. E2B records Yes.
• Idle cost — full-rate, 15th of 16. Fly.io Machines records free-when-stopped.
• Preview URLs — No. E2B records Yes.
• MCP server — No. Daytona records Yes.

None of these disqualify it on their own. They are the fields to check against your own requirements before you commit, because they are the ones where a competitor genuinely does better.

Provenance. 25 of 26 tracked fields carry a value for Self-hosted Firecracker, and 3 of those cite a document you can open. Last verified 2026-01-15. Every figure keeps its own provenance — measured by us, claimed by the vendor, inferred, or community-reported — and we would rather print a dash than a guess.

Its nearest neighbour in our data is ascii. Self-hosted Firecracker is ahead on Custom images (Yes against Partial). ascii takes Preview URLs (Partial against No). That pattern repeats across the rest of the roster — see Self-hosted Firecracker alternatives for the other rivals, each compared the same way.

Founded

2018

Licence

Apache-2.0 (open source)

Fields we track

25 of 26

Last verified

2026-01-15

The honest baseline. Compute is roughly a tenth of vendor pricing and the isolation is identical, because it is literally the same hypervisor. What you buy from everyone else is snapshot orchestration, pool warming, image distribution and multi-tenant quota enforcement — comfortably two engineer-years.

Cold start

200 ms3rd of 16

Inferred

Price / hour

$0.03 /hr1st of 9

Inferred

Streaming output

○No15th of 16

Inferred

Idle cost

full-rate15th of 16

Inferred

Preview URLs

○No18th of 19

Inferred

MCP server

○No12th of 16

Inferred

File up/download

○No19th of 19

Inferred

Concurrent limit

1,000 sandboxes1st of 13

Inferred

Self-hosted Firecracker is the right call in these situations, each one drawn from a field we actually record:

• Sustained volume where vendor margin exceeds an engineer's salary.
• Hard data-residency or air-gap requirements.
• You already operate bare metal and a scheduler.
• Cold start is your binding constraint. Self-hosted Firecracker records 200 ms, 3rd of 16 in the Sandbox providers roster. We define that field as p50 wall-clock from a single client in a fixed region calling create-sandbox on an account with nothing running, until a trivial command returns output.
• Price / hour is your binding constraint. Self-hosted Firecracker records $0.03 /hr, the best figure in the Sandbox providers roster. We define that field as list price for roughly 2 vCPU and 4 GB running for one hour on the cheapest paid tier, no commitment, excluding storage and egress.
• Concurrent limit is your binding constraint. Self-hosted Firecracker records 1,000 sandboxes, the best figure in the Sandbox providers roster.
• Sydney region is your binding constraint. Self-hosted Firecracker records Yes, which only 3 of the 16 tools in the Sandbox providers roster do.

Reach for something else when any of the following is a requirement rather than a nice-to-have:

• Streaming output. Self-hosted Firecracker records No on the Sandbox providers table. E2B records Yes on the same field. If that is a hard requirement rather than a preference, start elsewhere.
• Idle cost. Self-hosted Firecracker records full-rate, 15th of 16 in the Sandbox providers roster. Fly.io Machines records free-when-stopped on the same field. If that is a hard requirement rather than a preference, start elsewhere.
• Preview URLs. Self-hosted Firecracker records No on the Sandbox providers table. E2B records Yes on the same field. If that is a hard requirement rather than a preference, start elsewhere.
• MCP server. Self-hosted Firecracker records No on the Sandbox providers table. Daytona records Yes on the same field. If that is a hard requirement rather than a preference, start elsewhere.
• File up/download. Self-hosted Firecracker records No on the Sandbox providers table. E2B records Yes on the same field. If that is a hard requirement rather than a preference, start elsewhere.

We publish this block because a comparison that only lists what a tool is good at is marketing. Every figure above sits on the same page as its source, and the field definitions are on the category tables if you want to check how we measured them.

What we don't know. 1 of the 26 fields we track for Self-hosted Firecracker are still blank: Funding. Those render as dashes rather than as zeroes or assumptions, because an empty cell and a bad cell are not the same thing and only one of them is honest. If you know any of these figures and can point at a document, tell us.