Compare / Sandboxes
Modal vs Hotcell
Hotcell has no usage fees: it runs on hardware you already have. Hotcell runs on your own machines, as Firecracker or Apple Virtualization microVMs or Docker containers, and keeps real API keys out of every sandbox.
At a glance
| Modal | Hotcell | |
|---|---|---|
| Isolation | gVisor by default, with an optional VM runtime | Docker container, Firecracker microVM (Linux with KVM) or Apple Virtualization microVM (macOS) |
| Price | Sandboxes are billed at 3x list price per physical core: about $0.142 per core-hour, and one core is two vCPUs (calc). | Free and open source. You pay only for the hardware you run it on. |
| 2 vCPU, 4 GiB for an hour | $0.24 | $0 (your hardware) |
| Free tier | $30 a month of credits on the free Starter plan. Team is $250 a month. | Free, Apache-2.0. |
| Longest session | Default 5 minutes, up to 24 hours. | No limit; sandboxes run until you remove them. |
| Largest sandbox | Not published | Whatever your machine has |
| Pause and persistence | Filesystem snapshots kept 30 days; memory snapshots are in alpha and kept 7 days. | Pause takes a memory snapshot on the microVM drivers, so processes survive resume. |
| Start time (published) | Not published. | About 210 ms on the container driver; about 2.6 s for a cold microVM, faster from a warm pool. |
| GPUs | Yes | No |
| Self-hosting | No self-hosting or bring-your-own-cloud option found. | Yes, it only runs on your own hardware. Real API keys stay on the host; each sandbox gets a short-lived, spend-capped token. |
| SDKs | Python, JavaScript, Go | TypeScript, Python, plus CLI and REST |
| Real build benchmark | 7 of 7 phases, 105.5 s | Not on the leaderboard |
On a real coding-agent build
The open-source ComputeSDK sandbox-dax benchmark runs OpenCode's provider benchmark in each sandbox: install packages and Bun, clone OpenCode, bun install, then bun typecheck. Results from the run of 30 October 2026:
- Modal completed all seven phases in 105.5 s on a sandbox reporting 4 CPUs: clone 2.8 s, install 21.9 s, typecheck 64.4 s.
- On a bare-metal Ryzen 9 5950X at 32 vCPU, the same workload's clone, install and typecheck took 35.4 s (58.5 s for all seven phases), in July 2026 with Hotcell's own harness.
Each provider is one run, and sandboxes report different CPU counts, so treat small gaps as noise. For what this build needs from a sandbox, and what isolation costs, see our benchmark write-up.
Which should you choose?
Choose Modal if
- you need GPUs inside the sandbox
Choose Hotcell if
- you want no usage fees and already have a machine to run it on
- your agents run for longer than 24 hours
- you need pause and resume that keeps memory, not just files
- your code and API keys must stay on your own hardware
- you want real API keys kept out of every sandbox
More comparisons
Sources
- Modal: Modal pricing
- Modal: Modal sandboxes docs
- Hotcell: Hotcell
- Hotcell: Hotcell benchmarks
- Hotcell: Our benchmark write-up
- Benchmark: ComputeSDK sandbox-dax results
Prices change often. We check them by hand and the benchmark refreshes on every build; if something here is out of date, tell us.
FAQs
Is Modal cheaper than Hotcell?
Hotcell is cheaper. A sandbox with 2 vCPU and 4 GiB running for an hour costs about $0 there, against $0.24 on Modal.
Which is faster, Modal or Hotcell?
Modal completed all seven phases in 105.5 s on a sandbox reporting 4 CPUs: clone 2.8 s, install 21.9 s, typecheck 64.4 s. On a bare-metal Ryzen 9 5950X at 32 vCPU, the same workload's clone, install and typecheck took 35.4 s (58.5 s for all seven phases), in July 2026 with Hotcell's own harness. The workload is OpenCode's provider benchmark: clone, bun install and typecheck. Results are from ComputeSDK's run of 30 October 2026, one run each.
Can I self-host Modal or Hotcell?
Modal: No self-hosting or bring-your-own-cloud option found. Hotcell: Yes, it only runs on your own hardware. Real API keys stay on the host; each sandbox gets a short-lived, spend-capped token.