E2B
Open-source cloud sandboxes for AI agents, each a Firecracker microVM, with pause/resume, snapshots and forking. The safe default for most agent builders: mature, open source, microVM-isolated and widely supported.
Overview
E2B is the best-known agent sandbox and the default many AI frameworks reach for. Every sandbox is a Firecracker microVM with its own kernel, created in a call from the Python or JavaScript SDK. Beyond basic command execution, E2B ships a Code Interpreter SDK (Jupyter-style stateful execution with charts) and a Desktop SDK for computer-use agents.
State features have matured: pause/resume preserves memory and filesystem, running sandboxes can be snapshotted and forked, and paused sandboxes are kept indefinitely. The SDKs and backend runtime are Apache-2.0, with a self-hostable single-node package (“E2B Embed”) and Enterprise BYOC on AWS, Google Cloud or Azure.
Notable
- Raised a $21M Series A in July 2025, led by Insight Partners.
- Backend runtime (e2b-dev/runtime) is open source and self-hostable as “E2B Embed”.
- Ships dedicated Code Interpreter and Desktop (computer-use) SDKs.
E2B specifications
| Attribute | Details |
|---|---|
| Isolation | Firecracker microVM with its own kernel per sandbox |
| Deployment | Hosted platform · BYOC available · Self-hostable |
| Open source | Yes (Apache-2.0) |
| SDKs and interfaces | Python, JavaScript/TypeScript |
| Cold start (vendor claim) | Not documented |
| Max session length | Up to 1 hour continuous (Hobby), 24 hours (Pro) or custom (Enterprise); pausing resets the clock and paused sandboxes are kept until deleted |
| Persistence | Pause/resume preserves filesystem and memory; snapshots of running sandboxes, forking from a snapshot, filesystem-only snapshots, auto-resume and volumes (beta) |
| GPU | No — sandboxes are CPU-only |
| Networking | Internet on by default; can be disabled or restricted with allow/deny lists of IPs, CIDRs and domains; public sandbox URLs for exposed ports; custom domains and published egress IPs |
| Pricing | Per second: $0.000014 per vCPU-second (~$0.050/vCPU-hour) + $0.0000045 per GiB-second (~$0.016/GiB-hour). Pro plan $150/month plus usage; Enterprise from $3,000/month |
| Free tier | Hobby plan: $100 one-time credit, 20 concurrent sandboxes, 1-hour sessions |
| Compliance | SOC 2 Type II; HIPAA BAA and DPA available on request |
| Regions | Default region plus a shared EU cluster on request |
Facts from E2B’s public documentation, verified November 8, 2026. Performance numbers are vendor claims.
Strengths and trade-offs
Strengths
- You want the most widely integrated agent sandbox, with a large ecosystem of examples
- You need Firecracker microVM isolation for untrusted multi-tenant code
- You want an open-source codebase you can self-host or run via BYOC
- You want ready-made code-interpreter and desktop SDKs
Trade-offs
- CPU-only — no GPUs
- Session length capped at 1 hour on the free plan and 24 hours on Pro
- SDKs limited to Python and JavaScript/TypeScript
- Pro plan carries a $150/month platform fee
Best for: Code interpreters and short-to-medium-lived agent tasks that need microVM isolation, with an open-source self-host path.
Where E2B ranks
- Best sandboxes for coding agents — #2
- Best sandboxes for code interpreters and data analysis — #1
- Best sandboxes for reinforcement learning and agent evals — #3
- Best sandboxes for computer-use and browser agents — #2
- Best open-source and self-hosted agent sandboxes — #1
- Best agent sandboxes for enterprise and BYOC — #1
How E2B compares
| Sandbox | Isolation | Open source | Self-host / BYOC | Cold start (vendor) | Max session | Snapshots / pause | GPU | SDKs |
|---|---|---|---|---|---|---|---|---|
| E2B | Firecracker microVM | Yes | Yes / Yes | Not documented | 1 h / 24 h (Pro) | Yes / Yes | No | Python, JavaScript/TypeScript |
| Daytona | Containers or VMs | No | Not documented / Yes | <90 ms | Unlimited | Yes / Yes | Yes | Python, TypeScript, Ruby, Go, Java |
| Modal Sandboxes | gVisor or VM | No | No / Not documented | <1 s | Up to 24 h | Yes / Yes | Yes | Python, JavaScript/TypeScript, Go |
| Vercel Sandbox | Firecracker microVM | No | No / No | Milliseconds (claim) | 24 h (Pro) | Yes / Yes | Not documented | JavaScript/TypeScript, Python |
| Fly.io Sprites | MicroVM | No | No / No | 0.1–2 s wake | Unlimited | Yes / Yes | No | JavaScript/TypeScript, Go, Python, Elixir |
| Cloudflare Sandbox SDK | MicroVM (Containers) | Yes | No / No | 1–3 s | No fixed cap | Yes / Not documented | Not documented | TypeScript (Workers) |
| Blaxel | MicroVM | No | No / Yes | <25 ms resume | Unlimited (standby) | Yes / Yes | Not documented | TypeScript, Python, Go |
| Microsandbox | MicroVM (libkrun) | Yes | Yes / Yes | <100 ms | Not documented | Yes / Not documented | No | TypeScript, Python, Rust, Go, Ruby, CLI, MCP server |
Head-to-head: E2B vs Daytona · E2B vs Modal Sandboxes · E2B vs Vercel Sandbox · E2B vs Cloudflare Sandbox SDK · E2B vs Fly.io Sprites · Northflank Sandboxes vs E2B · Blaxel vs E2B · Together Code Sandbox vs E2B · Morph Cloud vs E2B · Freestyle vs E2B · AWS Bedrock AgentCore vs E2B · Microsandbox vs E2B
Frequently asked questions
What is E2B?
How does E2B isolate code?
Is E2B open source?
How much does E2B cost?
What are the best E2B alternatives?
Sources
Cite this page
Agent Sandboxes. (2026). E2B. agentsandboxes.org. Last reviewed November 8, 2026. https://agentsandboxes.org/sandboxes/e2b/
Found an error or a missing sandbox? Submit a correction — every entry links to the sources it relies on.