Encode and decode Base64, base64url and MIME with UTF-8-safe text for Arabic and emoji
Live HTML Preview
Write HTML, CSS and JavaScript and see the preview instantly in an isolated sandboxed iframe with a console for console messages, screen sizes, file download and code sharing in a compressed link.
Workspace
Console
How the result is calculated
The code is shown in an iframe via srcdoc with only sandbox="allow-scripts" (no allow-same-origin), so it runs in an isolated origin that cannot reach our site. A small script is injected before the content to forward console.log/info/warn/error and page errors through postMessage to the console. Updates are debounced by 350 ms after the last keystroke. Sharing: the code is compressed with CompressionStream("deflate-raw") and Base64URL-encoded in the #c= URL fragment (never sent to a server).
Limits:
A plain text editor (no CodeMirror, Emmet or syntax highlighting). Pages that need external resources follow browser policies. The share link length is limited (~6000 compressed characters). The preview is isolated, so features that need a same origin (localStorage, some browser APIs) do not work.
FAQ
Is the code I run safe?
It runs in an isolated iframe that cannot reach our site, but do not run code from a source you do not trust.
Where is the code in the link?
In the part after #, so it is never sent to a server.
