Cloud development environment powered by Firecracker microVMs with 2-second startup, environment branching, real-time collaboration, and Sandbox SDK for programmatic AI agent integration.
Instant cloud coding environments — preview and test web apps in seconds without setting up anything on your computer. AI agents can create and manage sandboxes programmatically.
CodeSandbox is a freemium cloud development environment and deployment platform starting at $0/month (Free) with paid plans from $9/month per user. It combines a browser-based IDE, Firecracker microVM infrastructure, and a programmatic Sandbox SDK into a unified environment for both human developers and AI agents. Originally launched as an in-browser playground for frontend prototyping, the platform has evolved into a full-stack development environment capable of running any Linux workload — Node.js, Python, Docker containers, databases, and native binaries — inside isolated microVMs that snapshot and resume in roughly two seconds. The core infrastructure, internally called Pitcher, uses AWS Firecracker to give each sandbox its own kernel and file system, providing stronger isolation than shared-kernel containers. When a sandbox goes idle, CodeSandbox snapshots the entire VM state — memory contents, running processes, installed packages, open network ports — to persistent storage. Reopening the sandbox restores from this snapshot instead of cold-booting, which eliminates the dependency-install and build-step delays that plague container-based cloud IDEs like GitHub Codespaces and Gitpod.
Environment branching is a standout feature: a single action forks a running microVM into an independent copy, including all in-flight state. Developers use this for parallel experimentation, and AI agents use it to explore multiple solution paths simultaneously before merging the best result. The Sandbox SDK (available for Node.js and Python) exposes this infrastructure programmatically — create, fork, snapshot, and destroy sandboxes via API — enabling AI product teams to embed isolated code execution into their own applications with kernel-level security boundaries.
Real-time collaboration is built into every sandbox: multiple users can edit files with live cursors, share terminal sessions, and view forwarded ports together without configuration. The platform connects to GitHub bidirectionally, supports automatic PR preview environments, and works across the browser editor, a VS Code extension, and JetBrains Cloud Containers plugin, so teams are not locked into a single editor.
CodeSandbox is used by individual developers for rapid prototyping and demos, by engineering teams as a Codespaces alternative for onboarding and PR reviews, and by AI companies (via the Sandbox SDK) as infrastructure for coding agents, data-analysis copilots, and interactive tutorials. The free tier provides monthly VM credits for prototyping; Pro ($9/month per user) unlocks private sandboxes and larger VMs; Team ($20/month per user) adds shared workspaces, role-based access, and team credit pools; and the Sandbox SDK uses usage-based pricing starting at approximately $0.005 per VM-minute with enterprise plans offering dedicated capacity and SLAs.
Was this helpful?
CodeSandbox has matured from a frontend playground into a capable cloud development platform with unique strengths in environment branching and collaborative editing. The Sandbox SDK for AI integration positions it as a bridge between pure code execution platforms (E2B) and traditional cloud IDEs (Gitpod, GitHub Codespaces). Users praise the instant environments and real-time collaboration, while common complaints center on credit consumption on the free tier and browser editor limitations. The platform is best suited for teams that value fast environment startup, parallel experimentation via branching, and programmatic sandbox creation for AI agent products.
Every sandbox runs inside an AWS Firecracker microVM with its own kernel and isolated file system. Snapshots of the full VM state are taken on idle and restored on resume, so reopening a project skips boot, dependency install, and build phases — typical resume time is around two seconds even for full-stack environments with running databases.
A single action forks the current microVM — including running processes, installed packages, open ports, and in-memory state — into a new independent VM. This enables parallel exploration of refactors, A/B testing of agent strategies, and lightweight 'what if' branches without re-bootstrapping the environment.
Node.js and Python SDKs expose microVM lifecycle (create, fork, snapshot, destroy), file system access, command execution, and port forwarding through a programmatic API. Designed for embedding inside AI agent backends, it supports persistent state across sessions and kernel-level isolation suitable for executing untrusted LLM-generated code.
Multiple users can edit the same files simultaneously with live cursors, share a single terminal session, and view forwarded ports together. Built-in to every sandbox without separate setup, making it suitable for pair programming, interviews, workshops, and live debugging sessions.
Developers can work in the browser-based web editor, the official VS Code extension, or the JetBrains Cloud Containers plugin — all backed by the same remote microVM. This lets individual contributors keep their preferred local editor while the team shares a consistent cloud environment.
Repositories sync bidirectionally with GitHub, and pull requests can automatically spin up ephemeral preview environments built from the same microVM snapshots, giving reviewers a working app to test rather than just a diff.
$0
$9/month per user
$20/month per user
Usage-based, ~$0.005/VM-minute; custom enterprise pricing
Ready to get started with CodeSandbox?
View Pricing Options →CodeSandbox works with these platforms and services:
We believe in transparent reviews. Here's what CodeSandbox doesn't handle well:
Weekly insights on the latest AI tools, features, and trends delivered to your inbox.
Through 2025 and into 2026, CodeSandbox has leaned heavily into the agent infrastructure thesis. The Sandbox SDK has matured with first-class Python support, snapshot and fork primitives exposed programmatically, and improved persistent state across sessions — all aimed at coding-agent and AI-tutor product teams. Environment branching, originally a power-user feature, is now a core selling point for agent workflows that need to explore multiple solution paths. The browser editor has received incremental improvements but remains secondary to the SDK and infrastructure story.
Deployment & Hosting
Secure cloud sandboxes for AI code execution using Firecracker microVMs. Purpose-built for AI agents, coding assistants, and data analysis workflows with hardware-level isolation and sub-second startup times.
Integrations
Cloud-based development platform with Agent 3 AI for autonomous coding across 50+ programming languages with real-time collaboration and MCP integration.
No reviews yet. Be the first to share your experience!
Get started with CodeSandbox and see if it's the right fit for your needs.
Get Started →Take our 60-second quiz to get personalized tool recommendations
Find Your Perfect AI Stack →Explore 20 ready-to-deploy AI agent templates for sales, support, dev, research, and operations.
Browse Agent Templates →