Playground
Write a small program. Run it. Inspect the result.
The online Playground opens with a one-line example. Edit it, choose Run code, and inspect Output. Your source is sent to the server only when you run or explicitly save it. The result identifies the responding engine.
Source and Output
On a large screen, source and output sit side by side. On a phone, use the Source and Output tabs. Running switches to Output; return to Source to continue editing. A failed request does not clear your program.
Examples and files
Choose Examples for a print statement, a reducer, guards, or list iteration. Examples and saved snippets open in a new tab without replacing your current source. Use the plus button to start a blank file. File → Undo close restores the last closed tab.
Local drafts, private saves, and sharing
Drafts are saved in this browser when local storage is available. They are not a server backup and are not automatically published. If browser storage is unavailable or another browser tab changes the drafts, a warning appears. Download your source before leaving.
File → Save privately makes a server copy. A signed-in account, or the recovery cookie in the browser that saved anonymously, controls access. Share a copy creates a separate secret link. Anyone with that complete link can retrieve the shared source until its owner revokes access. Revocation cannot remove copies someone has already downloaded.
To retrieve a saved copy, use File → Open snippet and paste its ID or complete shared link. Download .sig saves a local file without publishing it.
Keyboard and editor settings
| Action | Control |
|---|---|
| Run source | Ctrl / ⌘ + Enter |
| Private save | Ctrl / ⌘ + S inside the workspace |
| Move to another control | Tab, by default |
| Indent with Tab | Enable in File → Editor settings. Escape, then Tab exits the editor. |
| Wrap long lines | File → Editor settings. Line numbers are hidden while wrapping. |
| Find a page or topic | Ctrl / ⌘ + K |
Execution status
Output is displayed only after a response. If you change the source afterward, its status identifies the older result. Stop waiting cancels the browser’s wait, not a guaranteed stop of server execution. The displayed time measures the network round trip, not compiler performance.
The online runner is not proof that all compiler backends behave identically. Check the backend reference and verify the actual toolchain for your workload. Do not run source containing secrets.