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HTML Formatter

Format and beautify HTML with proper indentation. Free online tool to clean up messy markup in your browser instantly. Supports html, format.

HTML Formatter is a free online developer tool that works right in your browser — whatever you enter is processed locally and never sent to a server. No installation, no signup; works on both phone and desktop, ready to use instantly.

Code tools designed for developers with syntax highlighting, real-time validation, and formatting. Full coverage of JSON, XML, YAML, SQL, and more.

How to use

  1. 1 Open the HTML Formatter tool page.
  2. 2 Paste your text, URL, or data into the input area.
  3. 3 Choose the operation mode and parameters.
  4. 4 Run the tool and review the result.
  5. 5 Copy or download the result.

Why we built this tool

As developers ourselves, we kept switching between scattered tools that sent our code to unknown servers. We built this developer suite so formatting, validation, and conversion all run locally — your code stays yours.

About HTML Formatter: what you should know

Backend and frontend developers juggling multiple formats and protocols every day. When a third-party service returns data in an unfamiliar shape, or when you need to transform a payload before passing it along, this tool is the fastest way to bridge the gap without writing a throwaway script.

Key features

  • Privacy-First Local Execution — All processing happens inside your browser. Your code never leaves the device, which matters when the input contains internal API keys, customer data, or proprietary logic.
  • Copy-Ready Output — Results are formatted cleanly and ready to paste into your editor, terminal, or documentation. One-click copy puts the transformed data on your clipboard immediately.
  • Precise Error Reporting — If your input contains an issue, the tool points to the exact location instead of giving a vague error. This saves minutes of hunting for a misplaced character or invalid structure.

Common use cases

  • Preparing Data for Documentation — Format snippets before adding them to README files, API docs, or internal wikis. Clean output makes your documentation look professional.
  • Debugging API Output — When a service returns unexpected output, paste it here to transform it into something readable. Spot the issue fast and get back to fixing the real bug.

Frequently Asked Questions

Is this tool free?

Yes, completely free with no signup required.

Can I use it on mobile?

Yes, it works on mobile browsers with touch support.

What category does this belong to?

Developer

Which programming language formats are supported?

Supports JSON, XML, YAML, SQL, CSV, TOML and more, plus code format conversion for Java, Python, TypeScript, etc.

What code and data formats are supported for formatting and validation?

ToolPure supports JSON, XML, YAML, TOML, CSV, SQL, and Markdown formatting. Validation includes syntax checking, schema validation for JSON, and well-formedness checking for XML.

Can I convert between different data formats?

Yes, you can convert between JSON, XML, YAML, CSV, and TOML. The converter preserves data types, nested structures, and array indices during conversion.

Is there a file size limit for code formatting?

Files up to 10MB can be formatted without issues. For larger files, the tools use Web Workers to prevent UI freezing. Syntax highlighting supports files with up to 100,000 lines.

Is HTML Formatter safe? Is my data uploaded or stored?

Yes. HTML Formatter is a pure front-end tool: whatever you type or paste is processed only in your browser's memory and never sent to a server. It disappears as soon as you refresh or close the page.

🔒 Privacy & Security：All processing happens locally in your browser. Files are never uploaded or stored.

🔒 Privacy: All processing happens locally in your browser. Your files and data never leave your device — no upload, no server, no tracking.

Related tools

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📖 How-To Guides

💸 Paid Tool Alternatives

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