HTML Formatter & Beautifier
Usage Guide
HTML Formatter is an online tool for cleaning up and indenting HTML markup with zero server involvement. Messy, minified, or machine-generated HTML is notoriously difficult to read and debug: deeply nested tags collapse into single unreadable lines, inconsistent indentation obscures the document hierarchy, and hidden whitespace causes mysterious rendering differences. This tool solves those problems in one click. Paste any HTML snippet or full page source into the input area and the formatter instantly produces cleanly indented output that reflects the true structure of your document tree — html, head, body, each nested element at its own indentation level. The tool respects inline elements such as span and a, keeping them on the same line as their parent text, while block elements like div, section, article, and heading tags each occupy their own line. You can customise the indentation width to match your project's coding standards — 2 spaces, 4 spaces, or tab characters. The formatter also works beautifully with HTML email templates, Jinja/Django/Nunjucks template files, and component-level fragments. Because the tool runs locally in your browser, you can safely format HTML containing passwords, private API endpoints, or confidential business content.
- Paste your HTML — Click the input panel and paste any HTML content — a full document, a partial snippet, a template fragment, or minified output from a build tool.
- Upload a file (optional) — Drag an .html or .htm file onto the file-drop zone, or click the upload icon to open the file picker. File contents load directly into the input panel.
- Set indentation preference — Use the indentation selector to choose 2 spaces (default), 4 spaces, or a tab character. This setting is remembered in the URL so shared links preserve your preference.
- Click Format — Press the "Format" button. The right output panel fills with cleanly indented HTML. Block-level elements like div, p, section, and article each appear on their own line; inline elements stay inline.
- Review the structure — Read through the output to verify nesting is correct. Indentation makes it easy to spot unclosed tags, incorrectly nested elements, or unexpected whitespace that could affect rendering.
- Copy or download — Click "Copy" to copy the formatted HTML to your clipboard, or "Download" to save it as a .html file. The file name includes a timestamp so successive downloads do not overwrite each other.
Frequently Asked Questions
Is my HTML code sent to a server when I format it?
No. This HTML formatter runs entirely in your browser using native JavaScript. Your markup is never transmitted to any server or stored anywhere outside your device.
Can I format HTML offline?
2Kit is a Progressive Web App (PWA). After your first visit the tool is cached by the service worker and works completely offline — no internet connection required.
Does the tool handle HTML fragments (not full documents)?
Yes. The formatter auto-detects whether the input starts with <!DOCTYPE> or <html> and renders accordingly. For snippets it enters "fragment mode" and formats only the provided markup without injecting any surrounding document structure.
What does the DOM tree view show?
The right-hand panel parses your formatted HTML into a live DOM tree. Tag names appear in blue, attribute names in amber, attribute values in green, and text content in grey italics. Elements with children can be collapsed or expanded with a click.
Is this HTML formatter free?
2Kit is completely free, requires no account or registration, and has no usage limits. It is funded by no advertising and collects no personal data.
Technical Implementation
All processing runs entirely in your browser — no data is ever sent to any server. This tool works fully offline as a Progressive Web App (PWA): after the first visit, all pages and assets are cached by a Service Worker and remain available without an internet connection. Your input data never leaves your device, making it safe for sensitive content including API keys, passwords, private configuration, and confidential documents.