Head to head
E2B vs Fly.io Machines
A side-by-side, sourced comparison. Facts come from each vendor’s own materials; scores are our editorial opinion applied by the same rubric to both.
| Dimension | ||
|---|---|---|
| Pricing | Hobby (free) includes a one-time $100 usage credit, up to 1-hour sessions, and 20 concurrent sandboxes. Pro is $150/mo + usage (24-hour sessions, up to 100 concurrent). Usage is per-second (e.g. 1 vCPU at $0.000014/s).source ↗ | Usage-based, billed per second while running (e.g. shared-cpu-1x/256MB roughly $2/mo; performance-1x/2GB roughly $32/mo). Volumes are $0.15/GB-month and egress varies by region. No standing free tier is advertised.source ↗ |
| Hosting model | Hosted cloud that spins up on-demand secure Linux VM sandboxes reachable both internally and via a sandbox URL; self-hostable given the open-source codebase.source ↗ | Hardware-virtualized micro-VMs on Fly-operated servers across 18 documented regions on six continents.source ↗ |
| Memory & state | Sandbox persistence — pausing saves both filesystem and memory state, and connect() resumes the identical state, with paused sandboxes kept indefinitely. This is infrastructure state, not agent/LLM memory.source ↗ | Durable state via Fly Volumes (persistent block storage) and snapshots; Machines can be persistent or stopped (stopped root filesystem is retained). Machine RAM itself is ephemeral.source ↗ |
| MCP support | Nativesource ↗ | Nativesource ↗ |
| Integrations | First-party Python and JS/TS SDKs, Templates for defining environments, and MCP tools from a Docker catalog (Browserbase, Stripe, GitHub, Notion, and more).source ↗ | A Machines REST API and flyctl CLI, Fly Launch for containerized deploys, and a native fly mcp command surface with client wiring for major editors.source ↗ |
| Model providers | Model-agnostic — you bring your own LLM; E2B runs the code and tools, not the model.source ↗ | Not applicable — pure compute/hosting; commonly used to host MCP servers and AI workloads.source ↗ |
| Open source | Yessource ↗ | NoUnverified |
| Developer experience(opinion) | 4/5 | 4/5 |
| Pricing transparency & value(opinion) | 4/5 | 3/5 |
| Scalability(opinion) | 4/5 | 5/5 |
| Memory & state(opinion) | 3/5 | 3/5 |
| Integrations(opinion) | 3/5 | 3/5 |
| MCP nativeness(opinion) | 4/5 | 4/5 |
The balanced view
Editorial opinion, derived from the scorecard above
Where E2B scores higher
In our rubric, E2B rates ahead on pricing transparency & value.
Where Fly.io Machines scores higher
In our rubric, Fly.io Machines rates ahead on scalability.
These two serve different needs — read the full dossiers for E2B and Fly.io Machines before deciding. Neither has been hands-on tested by us yet.
Product and company names are trademarks of their respective owners and are used here only to identify the products under discussion.