CodeSandbox

CodeSandbox lets you spin up a development environment in the browser or in VMs that start from a snapshot. You can fork a project, edit it with teammates and share a live preview link with one click.

Its microVM-based sandboxes are also offered as an SDK, which AI agent builders use for running generated code. Developers use the regular editor for prototypes, tutorials and quick fixes without cloning anything.

Free usage is limited, and heavy teams will need a paid plan. For sharing a working example or reviewing a pull request in a live environment, it is very convenient.