HTML Formatter

Definition

Format HTML in the browser. On JSON Nova, the workflow runs entirely in your browser with no server processing of your data. Suitable for sensitive payloads, large files, and offline use as a PWA.

Format HTML in the browser. Private. For dev workflows and asset prep. See also JSON to CSV, JSON Formatter, and JSON Validator.

Run everything in your browser with Monaco Editor on JSON Nova—100% client-side, no server uploads, large-file friendly. Install as a PWA for offline use.

Guide and tips

Developer guide

Short, practical notes—workflow, common mistakes, and pro tips—with links to related tools.

Format HTML consistently

Format HTML in the browser. Private. For dev workflows and asset prep.

All processing stays in your browser. Paste production-shaped samples without uploading secrets.

Editor-native behavior

Match project style (tabs vs spaces, width) before you commit.

Browse more in the [tools directory](/tools).

Common mistakes

Formatting minified production bundles you should not rewrite by hand—use the right tool for source files.

Mixing formatter output with linter rules that disagree (ESLint, Prettier conflicts).

Pasting secrets into shared sessions; keep tokens out of examples.

Pro tips

Format on save in the IDE; use this page for quick one-off fixes and reviews.

Browse more in the [tools directory](/tools).

Quick reference

What is this HTML tool?

Formats **HTML** locally. Useful before deploy or code review.

Use cases

  • Smaller assets (consistent style).
  • Readable HTML in docs.

Common errors

  • Syntax errors block format.
  • Very large files may be slow.

Best practices

Validate in your build. Pair with related language formatters in the same hub.

Performance and privacy

Performance

Leverage the power of Monaco Editor and Web Workers. Our toolkit is optimized for files up to 50MB, providing real-time transformations without lag.

Privacy

Your data stays local. Conversions and formatting run 100% in your browser—nothing is sent to our servers.

Frequently asked questions

FAQ

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What formatting engine does this use?

We use Prettier, the industry-standard code formatter used by millions of developers, running 100% in your browser.

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Does it fix broken HTML tags?

The formatter handles common issues like mismatched indentation and inconsistent quoting. For missing tags, a validator is recommended.

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Can I customize the indentation?

The formatter follows standard 2-space indentation rules, which is the most widely adopted convention for modern web development.

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Is my code shared or stored?

No. All formatting is performed locally on your device via JavaScript. Your code never leaves your computer.

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Does it work with HTML5?

Yes, our formatter fully supports all HTML5 semantic tags, custom elements, and attribute patterns.

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Can I use it for email templates?

Absolutely. It's a great tool for cleaning up messy inline styles or nested tables used in legacy email HTML.

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What is the maximum code size?

We support HTML files up to 50MB for real-time local formatting without performance lag.

More tools

Related developer tools

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TypeScript Formatter

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SCSS Formatter

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