CodeSandbox

CodeSandbox provides instant, browser-based development environments that let developers write, run, and share code without any local setup, spinning up a full sandbox for a web project in seconds directly from a URL. It's widely used for reproducing bugs, prototyping ideas, and sharing runnable code examples in documentation, since anyone with the link can view and edit a live, running project rather than reading a static code snippet or cloning a repository locally. Beyond quick sandboxes, CodeSandbox offers full cloud development environments that mirror a real local setup, including a proper file system, terminal access, and the ability to run resource-intensive builds, which teams use for onboarding new engineers instantly without them installing dependencies on their own machine, and the same underlying sandboxing technology now also powers isolated code execution environments for AI coding agents. Its live collaboration features let multiple developers edit the same sandbox simultaneously, similar to a collaborative document, which is useful for pair programming, live interviews, or working through a bug together in real time. CodeSandbox integrates with GitHub so sandboxes can be created directly from a repository and changes committed back, keeping the fast prototyping workflow connected to a team's real codebase rather than existing as a disconnected scratchpad. It's popular with frontend teams, open-source maintainers, and educators who need to share runnable, editable code instantly instead of relying on screenshots or static gists.