Does this HTML editor show a live preview?

No. It highlights and helps you edit markup, but it doesn't render the page. To see the result, click Download to save an .html file and open it in any browser, or paste the code into a local file and refresh the browser tab after each change.

Will it tell me if my HTML is invalid?

No. The editor colors tags, attributes and values but doesn't validate them, and browsers quietly repair most broken markup, so mistakes can go unnoticed. Run finished pages through the W3C Nu HTML Checker at validator.w3.org/nu to catch unclosed elements, duplicate ids and missing alt text.

Are the CSS and JavaScript inside my HTML highlighted too?

Yes. Code inside elements is highlighted as CSS and code inside elements as JavaScript, so a single-file page reads properly. For larger stylesheets or scripts, the separate CSS and JavaScript editors save files with the right extension.

Is my code saved anywhere?

No. Everything stays in the browser tab and nothing is sent to a server. Reloading or closing the page clears it, so copy or download your work first.

The Tab key indents instead of moving to the next button. How do I leave the editor with the keyboard?

Tab is used for indentation inside the editor. Press Escape first and then Tab, and focus moves out of the editor to the next element on the page.

HTML Editor Online (Free, No Signup)

What this HTML editor is for

HTML (HyperText Markup Language) is the markup that gives every web page its structure: headings, paragraphs, links, images, forms and the containers that CSS styles and JavaScript controls. This editor is a place to write or clean up that markup in the browser, with highlighting, tag auto-closing and a one-click .html download.

It's handy for drafting an email template, building a quick prototype page, fixing a snippet before pasting it into a CMS, or practising while you work through a tutorial. The editor highlights code inside <style> and <script> blocks as CSS and JavaScript, so a self-contained page stays readable.

There is no live preview. The page doesn't render your markup, run your scripts or apply your styles. See "Previewing your page" below for the quickest way to view it.

What you can do in the editor

Syntax highlighting for elements, attributes, values, comments and embedded CSS/JS.
Tag auto-closing: type <section> and </section> is added for you.
Find / Replace across the whole document, one match or all at once.
Word Wrap for long lines of text content.
Dark Theme and Full Screen for longer sessions.
Copy to the clipboard, or Download as index.html.

A starter page to paste in

This is a complete, valid HTML document with a small inline style and script. Paste it in to see how each part is colored:

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Newsletter signup</title>
  <style>
    body { font-family: system-ui, sans-serif; max-width: 32rem; margin: 2rem auto; }
  </style>
</head>
<body>
  <main>
    <h1>Join the newsletter</h1>
    <form id="signup">
      <label for="email">Email address</label>
      <input id="email" name="email" type="email" required autocomplete="email">
      <button type="submit">Subscribe</button>
    </form>
    <p id="status" aria-live="polite"></p>
  </main>
  <script>
    document.getElementById("signup").addEventListener("submit", (event) => {
      event.preventDefault();
      document.getElementById("status").textContent = "Thanks! Check your inbox.";
    });
  </script>
</body>
</html>

Previewing your page

Click Download. The file saves as index.html, the name web servers serve by default for a folder.
Double-click the file, or drag it into any browser window. It opens from your disk with no server needed.
Edit, save, and press F5 to refresh. Open the browser's developer tools (F12) to inspect elements and read any script errors in the Console tab.

One catch: pages opened straight from disk use a file:// address, and browsers block some features there, including <script type="module"> imports and fetch() calls to local files. If you hit that, serve the folder over HTTP instead. Running npx serve or python -m http.server in the folder works, then open the address it prints.

Markup rules worth knowing

These come from the WHATWG HTML Living Standard, the specification browsers implement.

Rule	Why it matters
Start with `<!DOCTYPE html>`	Without it, browsers render in quirks mode, which changes how box sizes and tables behave
Put `<meta charset="utf-8">` early	The spec requires the encoding declaration to fit within the first 1024 bytes of the file, or accented characters can come out garbled
Void elements have no end tag	`<input>`, `<img>`, `<br>` and `<meta>` never take `</input>`. A trailing `/>` is allowed on them but has no effect, and on a normal element like `<div/>` it's ignored, leaving the div open
Every `id` must be unique	A `<label for="email">` connects to the first element with that id, so duplicates break form labels and `getElementById`
Images need `alt` text	Screen readers read it aloud; use `alt=""` for purely decorative images

Browsers recover from most mistakes silently, so a page can look fine while still being invalid. Before publishing, run it through the W3C Nu HTML Checker.

Keep learning

Work through the free HTML course or keep the HTML cheat sheet open while you type. When a page is finished, the HTML minifier strips whitespace and comments for production, and the code beautifier re-indents markup copied from somewhere messy. To write the stylesheet separately, switch to the CSS editor.

HTML Editor