Last updated: 2026-08-25
E2B is a cloud sandbox platform that lets AI agents execute untrusted code inside Firecracker microVMs, with cold starts around 80 milliseconds in the same region. It is built for coding copilots, data-analysis tools, and autonomous agents that need to run AI-generated code safely, not for hosting consumer-facing apps.
About E2B
E2B is a cloud sandbox platform, founded in 2023, that gives AI agents an isolated place to run untrusted code. The company closed a $21M Series A led by Insight Partners in July 2025 to grow its enterprise sandbox infrastructure. Every sandbox runs on Firecracker, the same microVM hypervisor AWS built for Lambda, so code cannot break out to the host machine or to another customer's sandbox even if it is malicious. Teams can build custom Docker-based templates to pre-load dependencies and libraries for a specific use case before spinning up new sandboxes. In October 2025, Docker and E2B partnered so every sandbox can reach the Docker MCP Catalog and its 200+ external tools, including GitHub, Perplexity, Browserbase, and ElevenLabs. Enterprise customers can also run E2B as Bring Your Own Cloud (BYOC) inside their own AWS VPC instead of the managed service.
Screenshots
Pricing
Hobby: free to start, no credit card required (see the free-tier FAQ for the exact credit and limits). Pro: $150 per month base fee, plus per-second usage billing near $0.05 per vCPU-hour once code is actually running. Enterprise: custom pricing with a $3,000 per month minimum, covering BYOC and on-premises deployment.
Feature Comparison by Tier
| Feature | Pro | Hobby | Enterprise |
|---|---|---|---|
| Sandbox runtime (Python/JS) | ✓ | ✓ | ✓ |
| Concurrent sandboxes | 100 | 20 | Custom |
| Max sandbox lifetime | 24 hrs | 1 hr | Custom |
| Custom Docker images | ✓ | — | ✓ |
| SOC 2 compliance | — | — | ✓ |
Key Features
- Firecracker-Based Isolation: Every sandbox boots inside a Firecracker microVM, the same hardware-level isolation AWS uses for Lambda, with sub-second cold starts in the same region so untrusted code cannot reach the host or other customers' sandboxes.
- Multi-Language Code Execution: Runs Python, JavaScript/TypeScript, Ruby, Go, and C++ side by side with pre-installed package managers, so agents can execute mixed-language workloads without extra setup work.
- Code Interpreter SDK: Dedicated Python and JavaScript SDKs wrap sandbox creation and code execution into a few function calls, built for coding copilots, data-analysis tools, and agent frameworks.
- Docker MCP Catalog: The October 2025 Docker partnership gives every sandbox access to 200+ pre-built integrations, including GitHub, Perplexity, Browserbase, and ElevenLabs, through the Docker MCP Catalog.
- Custom Docker Templates: Teams can build their own Docker-based templates to pre-configure libraries and environment variables once, then reuse that template across every new sandbox for a given workload.
- BYOC Deployment: Enterprise plans can run entirely inside a customer's own AWS VPC (Bring Your Own Cloud) or on-premises instead of E2B's managed cloud, for teams with strict data-residency rules.
Pros
- Firecracker's kernel-level isolation is the reason security teams trust E2B with AI-generated code that a plain container would not contain as safely.
- Heavy adoption among large enterprises shows this is a production-tested platform, not an early-stage experiment, and the open-source core means teams are not fully locked into E2B's hosted service.
- BYOC and on-premises deployment make E2B usable for regulated industries that cannot send code execution to a shared third-party cloud.
Cons
- Sandbox sessions cap out at 24 hours even on the Pro tier, which rules E2B out for agents that need to stay alive indefinitely in the background.
- The standard concurrency ceiling makes E2B expensive to scale past a certain point, since going higher requires negotiating a custom enterprise contract instead of paying the listed price.
- Every sandbox interaction crosses the network, so round-trip latency adds up for agent workflows that call code execution many times in a row.
Product Information
- Cloud
- Yes
- Self-Hosted
- Yes
- On-Premise
- No
- Languages
- English
- Training
- Documentation (e2b.dev/docs), Python SDK, JavaScript SDK, Community Discord
Data Handling
- Compliance
- SOC 2 (cloud) · GDPR · HIPAA (Enterprise)
Frequently Asked Questions
What does E2B actually cost?
E2B's Hobby tier is free to start, no credit card needed. The Pro plan runs $150 a month as a base fee, with metered compute billed by the second once a sandbox is live. Enterprise pricing is negotiated separately, starting around $3,000 a month for BYOC or on-premises setups.
What do you get on E2B's free tier?
The Hobby plan is free forever and comes with a $100 signup credit, no card required. Sessions are capped at 1 hour with up to 20 sandboxes running at once, which suits prototyping but not sustained production traffic.
Which tools compete with E2B in 2026?
On hokai, the nearest matches are Replit and Cursor, though neither is a true substitute for E2B. Replit is a persistent cloud IDE meant for a person to write, run, and deploy code from a browser. Cursor is an AI-first code editor where a developer reviews generated code by hand before running it, while E2B is the automated layer that executes and checks code on an agent's behalf.
What separates E2B from Replit?
Replit's environments are long-running developer workspaces without Firecracker-level isolation between tenants, while every E2B sandbox boots in its own microVM with hardware-level separation from other customers' code. That isolation is why security-conscious teams pick E2B when an AI agent, not a person, is the one issuing the run-code command.
How do you get started with E2B?
Install the Python or JavaScript SDK and grab an API key from the E2B dashboard, then call one function to spin up a sandbox and run code inside it. The free Hobby plan requires no payment details up front, so most developers have a working sandbox running within minutes, with custom Docker templates layered in later.
Top Alternatives
- Replit: Pick Replit for a full cloud IDE with human-facing deployment; pick E2B when AI agents need ephemeral, isolated code execution environments that spin up in milliseconds.
- Cursor: Choose Cursor for IDE-first AI coding; choose E2B when the goal is giving your AI agent a sandboxed execution layer that runs and verifies code programmatically.
HokAI guides covering E2B
- AI Development Services in 2026: Which Layer You Actually Need: AI development services means four separate infrastructure layers, not one purchase: sandboxing, prompt testing, workflow durability, and API governance.
- The AI Tool Ecosystem in 2026: Buy the Meter, Not the Category: Four meters set your AI infrastructure bill: tokens, machine seconds, vendor credits, seats. Modal, Replicate, E2B and Together AI priced August 2026.