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HTML Formatter

Beautify and pretty-print HTML code with proper indentation. Paste minified or messy HTML and get clean, readable output instantly.

Input HTML
Formatted HTML

About HTML Formatter — HTML Formatter Online

The Oneyfy HTML formatter online takes messy, minified, or poorly indented HTML and produces clean, properly nested, human-readable output in one click. Paste any HTML — generated by a CMS, exported from a design tool, received from an API, or copied from a browser's view-source — and immediately get a version that is easy to read, edit, and debug. Choose 2-space, 4-space, or tab indentation to match your project's coding standards.

Web developers use an HTML formatter online whenever they need to understand or edit HTML that was not written by hand. CMS-generated markup, email templates, minified production pages, and third-party widgets frequently arrive as single-line or inconsistently indented code that is nearly impossible to navigate. Formatting it first turns hours of manual search-and-indent work into a single paste-and-click operation.

How to Use the HTML Formatter

  1. Paste your HTML — minified, single-line, or just messily indented — into the Input HTML textarea on the left. There is no size limit enforced by the interface; large documents work fine.
  2. Select your preferred Indent style from the dropdown: 2 spaces is the most common convention for web projects, 4 spaces is standard for many style guides, and Tab satisfies editors configured for tab-based indentation.
  3. Click Format HTML. The formatted output appears instantly in the right panel with proper nesting and consistent indentation applied throughout the document.
  4. Review the output to confirm the formatting looks correct. The formatter preserves all your tag attributes, content, and comments — it only adjusts whitespace and line breaks.
  5. Click the Copy button in the output panel header to copy the formatted HTML to your clipboard, then paste it into your code editor, CMS, or document.

Formatter Features and Options

The HTML formatter provides several options to match your workflow and coding standards.

  • Configurable indentation: Switch between 2 spaces, 4 spaces, or a tab character for indentation. The choice persists across formatting runs during your session, so set it once and format multiple documents.
  • Block and inline element awareness: Block-level elements like <div>, <p>, <section>, and <ul> are placed on new lines with appropriate indentation. Inline elements like <span>, <a>, <strong>, and <em> are handled without unnecessary line breaks.
  • Comment preservation: HTML comments (<!-- ... -->) are kept intact and indented at the correct level, so notes and conditional comments are not lost during formatting.
  • One-click copy: The Copy button in the output panel puts the formatted HTML directly on your clipboard so you can paste it without selecting all text manually.

Tips for Getting the Best Results

These tips will help you use the HTML formatter effectively across different scenarios.

  • Format before editing, not after: If you receive HTML from a third party and need to modify it, format it first. Trying to edit single-line HTML is slow and error-prone; formatted HTML lets you see the structure at a glance and makes targeted changes without accidentally breaking sibling elements.
  • Use 2-space indentation for deeply nested HTML: HTML documents with many levels of nesting — tables inside divs inside sections inside articles — can produce very long lines with 4-space indentation. Switching to 2 spaces keeps deeply nested content visible without horizontal scrolling in most editors.
  • Paste view-source pages to understand third-party markup: If you need to understand how a competitor's or partner's page is structured, copy from browser view-source, paste it here, and format it. Minified production HTML is virtually unreadable until it is formatted.
  • Check that your paste is complete: Sometimes copying HTML from a browser source view cuts off at a character limit. If the formatter output looks incomplete or unbalanced, verify that your paste includes the closing </html> tag.
  • Format email templates carefully: HTML email clients are sensitive to certain whitespace changes. Formatting is useful for reading email templates, but do not paste the formatted output back into an email sender without testing — some email clients treat whitespace differently than browsers.

Why Use an HTML Formatter Online

Most code editors have HTML formatting built in, but they require a local development environment and a properly configured project. An HTML formatter online requires nothing — paste your code, choose your indentation, and copy the output. It is the fastest option when you are working on a device without your editor configured, collaborating with someone remotely, or formatting a one-off snippet that does not belong in a project.

Student web developers, technical writers documenting HTML structures, QA engineers reviewing page markup, and designers trying to understand how a layout works are the most frequent users of a browser-based HTML formatter. The tool handles everything entirely client-side, so sensitive internal HTML from staging environments or paywalled content never leaves your browser.

Frequently Asked Questions about HTML Formatter

No — the HTML Formatter focuses solely on formatting and indentation, not validation. It will format whatever HTML you provide even if the document contains errors, missing closing tags, or invalid attributes. To check HTML validity, use the W3C Markup Validator alongside this formatting tool. Formatting and validation are separate concerns and serve different purposes.
No. All formatting runs entirely in your browser using JavaScript. Your HTML code is never transmitted to any server or third party. This makes the tool safe to use with sensitive internal markup, staging environment HTML, or proprietary templates — your code stays on your device throughout the session.
Yes, completely free. There is no sign-up, no account, and no usage limit. Format as many HTML documents as you need at no cost. The tool is available directly in your browser any time.
Yes. The formatter has no enforced size limit — it processes whatever you paste into the input area. Very large documents (several megabytes of HTML) may take a fraction of a second longer to format, but the tool handles them without any upload restrictions since everything runs locally in your browser.
The formatter preserves the content of <style> and <script> blocks intact without reformatting the CSS or JavaScript inside them. This is intentional — CSS and JavaScript have their own formatting rules that differ from HTML indentation. Use a dedicated CSS or JavaScript formatter if you also need to format the code inside those blocks.
Yes. The HTML formatter works in any modern mobile browser. The two-panel layout stacks vertically on smaller screens so both the input and output areas are visible. Pasting HTML on mobile is easiest by long-pressing the input area and choosing Paste from the context menu.
Formatting adds whitespace and indentation to make HTML readable for humans — it increases file size. Minifying does the opposite: it removes all unnecessary whitespace, comments, and characters to reduce file size for faster page loads. Use formatting when you need to read or edit HTML; use minification when deploying to production. Oneyfy has a separate HTML Minifier tool for minification.
Different formatters make different decisions about line breaks for inline elements, self-closing tags, and attribute placement. This tool prioritizes simple, readable output over matching any specific editor's style (such as Prettier or VS Code's built-in formatter). If you need formatting that exactly matches a specific tool's style, use that tool directly — this formatter is best for quickly making unreadable HTML navigable.