Free HTML Beautifier Online
Format and beautify HTML code with proper indentation. Free, fast, and works entirely in your browser with no sign-up required.
Updated
HTML Beautifier
Format, beautify, and minify HTML code with validation, syntax highlighting, live preview, and advanced formatting options.
Formatting Options
Input HTML
Beautified HTML
Beautified HTML will appear here...
About HTML Beautifier
This tool formats, beautifies, and minifies HTML code with validation, syntax highlighting, live preview, diff comparison, and advanced formatting options.
Features:
- Beautify and minify modes with one-click toggle
- Syntax-highlighted output with color-coded tags, attributes, and values
- Live HTML preview in sandboxed iframe
- Side-by-side diff view comparing input and output
- HTML validation with errors, warnings, and accessibility suggestions
- Tag statistics: element counts, attribute counts, depth analysis, document assessment
- Customizable indent size (2, 4, 6, 8 spaces) and tabs
- Tag case transformation (lowercase, UPPERCASE, preserve)
- Attribute formatting: auto, one per line, aligned, or preserve
- Attribute sorting (id and class first, then alphabetical)
- Remove comments and empty tags options
- Drag-and-drop file upload with auto-format on paste
- Batch processing: upload and format multiple HTML files with error counts
- Undo/redo support with keyboard shortcuts
- History: save and reload previous formatting sessions (stored locally)
- Preferences are saved between sessions
- File upload (.html, .htm, .xml, .svg) and formatted download
Privacy First: All formatting happens locally in your browser. Your code is never sent to any server. Preferences and history are stored in localStorage.
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Frequently Asked Questions
What is the HTML Beautifier?
The HTML Beautifier is a free online tool that formats and indents HTML code properly for better readability and maintainability.
Is the HTML Beautifier free?
Yes, it is completely free with no registration required. All formatting happens client-side in your browser.
Can I customize the indentation?
Yes, the HTML Beautifier lets you choose between tabs and spaces and set the indentation width for your preferred code style.
Is my data safe with this tool?
Absolutely. The HTML Beautifier processes everything client-side in your browser. No data is uploaded to or stored on any server. Your content remains private on your device at all times.
Does the HTML Beautifier work on mobile devices?
Yes, the HTML Beautifier is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.
Do I need to create an account to use this tool?
No account or registration is needed. Simply open the HTML Beautifier in your browser and start using it immediately. There are no sign-up walls or usage restrictions.
How do I use the HTML Beautifier?
Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.
Which browsers are supported?
The HTML Beautifier works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.
What is the difference between beautifying and minifying HTML?
Beautifying and minifying are opposite operations. Beautifying adds indentation and line breaks so nested elements line up and the markup becomes readable, which is what you want while writing, debugging, or reviewing code. Minifying does the reverse: it strips that extra whitespace, line breaks, and optional characters to collapse the document down to the smallest equivalent output, which is what you ship to production to save bytes and speed up loading. Crucially, neither operation changes how the page renders in a browser, because HTML ignores insignificant whitespace between most tags. This tool does both: paste messy markup to format it for editing, or switch to minify mode to compress formatted HTML and see exactly how much smaller the result became. Beautify before you debug, minify before you deploy.
What problems does the HTML Beautifier flag in my markup?
Beyond formatting, the tool inspects your markup and reports issues as errors, warnings, or suggestions. It catches things that quietly hurt accessibility, SEO, and Core Web Vitals: <img> tags missing an alt attribute, and images missing explicit width and height, which is a common cause of layout shift (CLS). It flags structural gaps like a missing DOCTYPE declaration, an absent charset meta tag, and a missing viewport meta tag when a <head> is present. It also warns about <a target="_blank"> links that lack rel="noopener noreferrer", a security and performance best practice, plus deprecated attributes that belong in CSS. These checks run automatically as you paste, so you spot real problems while you clean up indentation. Paste your page to see the formatted output and the validation report side by side.
How does the beautifier handle elements with lots of attributes?
When a single tag carries many attributes, keeping them all on one line produces long, hard-to-scan lines that sprawl off the screen, which is common with <div>, <img>, and component-style markup. The HTML Beautifier can wrap attributes automatically once an element has four or more, placing each on its own indented line so the tag stays readable while shorter tags stay compact on one line. You can also set a maximum line length, choosing 80, 100, 120, or 160 characters, to control wrapping for long lines generally, and keep inline elements like <span>, <a>, and <strong> on the same line as their text. These options let the output match your team's style guide instead of a fixed format. Adjust the attribute and line-length settings, then copy the tidied markup straight to your clipboard.
Why is properly indented HTML easier to debug than minified code?
When indentation reflects the real DOM hierarchy, each nested element sits one level deeper than its parent, so the structure of the document is visible at a glance. That makes a misplaced closing tag or an unclosed <div> obvious instead of hiding inside one long, compressed line where everything runs together. Minified or machine-generated HTML removes that visual hierarchy entirely, forcing you to mentally parse where each element begins and ends. Beautified markup also produces cleaner diffs in Git, because formatting is consistent line by line, so code reviews focus on real changes rather than whitespace noise. For anyone learning HTML, indented source is simply easier to study than the wall of text most build tools emit. Paste any minified page and the readable version appears immediately, ready to debug or edit.
What does the nesting depth statistic tell me about my HTML?
Nesting depth measures how many levels of elements are stacked inside one another, from the outermost tag down to the deepest child. The beautifier reports the maximum depth in your document alongside other structural stats like line and byte counts and the number of unique tags. A high depth often signals over-nested layouts, where wrappers are piled on wrappers, which makes markup harder to read and maintain and can slow style and layout calculations in the browser. The tool labels shallow structures as good and warns when depth climbs into deep territory, giving you a quick signal to flatten unnecessary container elements. Reading the indentation makes deep nesting visible, and the depth number quantifies it. Paste your page to see its nesting depth and tag breakdown, then simplify the structure where the count looks unusually high.
Embed This Tool
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<p style="font-size:12px;margin:4px 0 0"><a href="https://getthetoolbox.com/code-tools/html-beautifier?utm_source=embed&utm_medium=widget" target="_blank" rel="noopener">Free HTML Beautifier Online</a> by The Toolbox</p>Related Tools
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About the HTML Beautifier
The HTML Beautifier is a free online tool that takes messy, minified, or machine-generated markup and rewrites it with clean indentation and consistent line breaks. Paste a single tag or an entire page, and it re-formats the structure so nested elements line up, opening and closing tags are easy to match, and the document becomes readable again. It is built for front-end developers, email coders, CMS users staring at a wall of compressed HTML, and anyone who has ever copied source from "View Page Source" and wished it had whitespace.
Everything runs locally in your browser. Your markup is parsed and formatted on your own device, never uploaded to a server, so it stays private even when it contains internal templates, draft content, or page source from a client site. There is no sign-up, no size paywall, and nothing to install.
What the beautifier does to your markup
- Indentation you control — choose 2 or 4 spaces (or tabs) per level so the output matches your team's style guide.
- Attribute formatting — keep attributes on one line, or wrap them automatically when an element has four or more, which keeps long
<div>and<img>tags from sprawling across the screen. - Sensible whitespace rules — preserve empty lines, keep inline elements like
<span>,<a>, and<strong>on the same line as their text, and optionally set a maximum line length (80, 100, 120, or 160 characters) for wrapping. - Cleanup options — strip empty tags, remove comments, sort attributes alphabetically, and protect specific tags (such as
svg,math, ortemplate) from being reformatted.
A minify mode does the reverse: it collapses formatted HTML back down to the smallest equivalent output and reports how much smaller the result is, which is handy before shipping to production.
Built-in validation and quality checks
Beyond pure formatting, the HTML Beautifier inspects your markup and flags common problems as errors, warnings, or suggestions. It catches things that quietly hurt accessibility, SEO, and Core Web Vitals, including:
<img>tags missing analtattribute, or missing explicitwidth/height(a frequent cause of layout shift, or CLS).- A missing
langattribute on<html>, absentcharsetorviewportmeta tags, and a missing<!DOCTYPE>declaration. <a target="_blank">links withoutrel="noopener noreferrer", and deprecated attributes likealignandbgcolorthat should be moved to CSS.
Alongside these checks it reports structural stats — line and byte counts, the number of unique tags, and the maximum nesting depth — so you can spot over-nested layouts at a glance.
Why clean HTML matters
Readable markup is faster to debug and safer to edit. When indentation reflects the real DOM hierarchy, a misplaced closing tag or an unclosed <div> becomes obvious instead of hiding inside one long line. Consistent formatting also produces cleaner diffs in Git, so code reviews focus on real changes rather than whitespace noise. For anyone learning HTML, beautified source is simply easier to study than the compressed output most build tools emit.
The tool is forgiving with imperfect input: it formats fragments and full documents alike and won't refuse to run on markup that isn't fully valid. For repeat work, you can upload .html files (or drag and drop them), process several at once in batch mode, compare a before-and-after diff, and undo or redo changes as you experiment with settings. When you're done, copy the result to your clipboard or download it as a file.
Using it day to day
Paste your HTML, pick an indent size, and the formatted output appears immediately. Toggle the advanced options only when you need them — for most pages the defaults produce tidy, conventional markup. Because all processing happens in your browser, the HTML Beautifier works offline once the page has loaded and handles large files at the speed of your own machine rather than a shared server.