An online HTML editor built for developers
Write HTML, CSS and JavaScript in separate tabs and see the result instantly. The preview runs your code in an isolated sandbox, the console shows logs and runtime errors, and the tool panels check your markup, accessibility and meta tags as you type. Everything runs in your browser — nothing is uploaded.
What you can do
| Area | Features |
|---|---|
| Code | Ace editor with syntax highlighting, line numbers, bracket and tag matching, auto-closing, code folding, find & replace, undo/redo, word wrap and basic autocomplete (Ctrl+Space) |
| Preview | Auto run or manual Run, refresh, full screen, open in a new tab, PNG screenshot, Fill/Desktop/Laptop/Tablet/Mobile sizes and a custom width × height; large sizes are scaled to fit |
| Visual | Edit the rendered page body: paragraphs, headings, bold, italic, underline, lists, links, images, buttons, quotes, tables, alignment, remove formatting |
| Format | Format HTML, CSS and JavaScript (js-beautify) with 2 spaces, 4 spaces or tabs; basic minifiers |
| Clean | Opt-in cleaners for inline styles, classes, IDs, comments, empty tags and paragraphs, whitespace, redundant attributes and trailing spaces — each explained first and undoable |
| Inspect | Console, basic HTML checks, accessibility checks, SEO/meta preview with a search-result and social card, code statistics, colors |
| Files | Open or drag & drop .html, .htm, .txt, .css and .js; download one HTML file or a project ZIP; templates; local autosave and history |
Simple mode and Project mode
Simple mode is one HTML document — paste a full page and edit it. Project mode gives you index.html, styles.css and script.js. The preview adds the CSS to the page head and the JavaScript to the end of the body automatically. If your HTML already links styles.css or script.js, those links are replaced by the tab contents. Download Project ZIP keeps the three files separate.
Visual mode: what it does and does not do
Visual mode lets you click into the rendered page and edit text and formatting. It only edits the body of index.html; the head, CSS tab and JavaScript tab are never changed. Scripts in the body are kept and moved to the end of the body, and inline event handlers (such as onclick) are restored when your edits are copied back. The browser normalises markup — quotes, spacing and some tag forms may change — so complex developer markup is best edited in Code mode. Every visual change can be undone in Code mode.
HTML cleaner
The Clean menu removes things only when you ask. Each action explains what it will remove before it runs, never touches the contents of <script>, <style>, <pre> or <textarea>, and can be undone with Ctrl+Z.
Privacy and security
- Your code, imported files and console output stay in your browser. Drafts and history are saved in local storage on your device.
- The preview runs in a sandboxed frame with no access to this page, your storage or the editor tab. Pop-ups it opens stay sandboxed.
- Analytics count visits and which features are used; they never receive your code or file names. See the privacy page.
Limitations
- Files referenced by relative paths (for example
images/logo.png) cannot load in an online preview. Use full https:// URLs. - Only one HTML page plus one CSS and one JavaScript file per project.
- The minifiers are basic: they remove comments and extra whitespace and keep JavaScript line breaks for safety.
- The HTML checks are not a full W3C validator.
- Server-side code such as PHP does not run.
Frequently asked questions
Is this HTML editor free?
Yes. It is free, needs no account and works in any modern browser on desktop and mobile.
Can I edit HTML, CSS and JavaScript separately?
Yes. Switch to Project mode to get three tabs: index.html, styles.css and script.js. The preview combines them automatically, so you do not have to link the files yourself.
Is my code uploaded to a server?
No. Editing, previewing, formatting, cleaning and checks all run in your browser. Your draft and history are saved only in your browser's local storage on this device.
Does the visual editor change my HTML?
Visual mode edits only the page body. Scripts are kept and inline event handlers are restored, but the browser rewrites markup formatting such as quotes and spacing, and scripts move to the end of the body. Every visual change can be undone in Code mode.
Can I download my project?
Yes. Download HTML saves one combined file. Download Project ZIP saves index.html, styles.css and script.js as separate files.
Is the HTML check a full W3C validator?
No. It runs basic checks such as missing doctype, title, viewport or language, duplicate IDs and tags that are opened and closed a different number of times. For full standards validation use the W3C Markup Validation Service.
Can I paste code from ChatGPT, Claude or Gemini?
Yes. Use Paste AI Code and paste the whole answer. The HTML, CSS and JavaScript code blocks are put into the right tabs. No AI service is contacted.
Related tools
Just want to view or check a page? Use HTML Viewer Online. Have a whole answer from an AI assistant? Use Preview AI-Generated HTML.