An online HTML editor lets you write and test HTML, CSS, and JavaScript code directly in your browser and see the rendered result in real time. Use it to prototype pages, test snippets, learn HTML structure, or debug layout issues — no installation or text editor required.
How to Use the Online HTML Editor
The online HTML editor provides a split-pane interface where your HTML source code sits on the left and a live rendered preview updates on the right. The preview runs inside a sandboxed iframe, which means it renders HTML, executes JavaScript, and applies CSS exactly as a real browser would — but safely isolated from the editor itself.
Writing and Running HTML
Type HTML in the code editor and the preview updates automatically after a short debounce delay. For larger documents, uncheck Auto-run and click the Run button to render on demand. Pressing Tab inserts 2 spaces instead of moving focus, so you can indent your code naturally.
Using Starter Templates
Click any template button above the editor to load a pre-built starting point. Hello World shows a minimal page structure. Bootstrap Starter loads Bootstrap 5 via CDN with a navbar and card. Simple Form provides a styled input form. CSS Grid Layout demonstrates a 3-column responsive grid. Templates auto-trigger the preview so you see results immediately.
Exporting Your Code
Click Copy HTML to copy your code to the clipboard, or Download HTML to save it as an .html file. Open the downloaded file in any browser or upload it directly to a web server. Your code is also auto-saved in localStorage so it persists between page visits.
Fullscreen Preview Mode
Click Fullscreen to open the rendered preview as a full-page overlay — useful for inspecting responsive layout behavior at full width. Close the overlay to return to the editor. The fullscreen iframe renders the same HTML that is currently in the editor.
FAQ
Is this HTML editor free?
Yes, the online HTML editor is completely free with no account required. Write, preview, and download HTML without any limits.
Is my HTML code saved?
Your HTML content is stored in your browser's localStorage so it persists between sessions. Nothing is sent to any server — all processing happens entirely in your browser.
Is the preview sandbox safe?
Yes. The preview runs in a sandboxed iframe with 'allow-scripts' permission. It prevents the preview from navigating the parent page or accessing cookies. You can safely test JavaScript code in the preview without risk to this page.
How do I use the starter templates?
Click any template button above the editor — Blank, Hello World, Bootstrap Starter, Simple Form, or CSS Grid Layout — to load a pre-written HTML example. You can edit it or use it as a starting point for your own page.
Does Tab key insert spaces in the editor?
Yes. Pressing Tab while editing inserts 2 spaces at the cursor position, so you can indent your HTML naturally without switching focus to another element.
How do I download my HTML file?
Click the Download HTML button in the toolbar to save your current HTML content as an .html file that you can open in any browser or deploy to a web server.
Can I use this to test JavaScript?
Yes. The sandboxed preview executes JavaScript embedded in script tags. You can use it to prototype small scripts, test DOM manipulation, or experiment with browser APIs.