Runs fully in your browser. Inputs stay on your device. See recent fixes on changelog.
HTML Formatter & Validator
Format, beautify, and validate HTML code.
FreeRuns in browserhtml formatterhtml beautifier
Cmd/Ctrl+Enter Primary actionCmd/Ctrl+Shift+L Load sampleCmd/Ctrl+Shift+X Clear/resetCmd/Ctrl+Shift+C Copy result
About HTML Formatter & Validator
Format, beautify, and validate HTML code. Format, validate, and beautify HTML code online for free. Fix indentation, check for mismatched tags, and clean up messy markup instantly in your browser. Applies consistent indentation and style rules across your entire document with one click. Validation mode checks syntax correctness and reports detailed, actionable error descriptions. Everything runs client-side in your browser for maximum speed and privacy — no data is sent to any server, and no signup is required.
Related tools: CSS Formatter & Beautifier, JavaScript Formatter, HTML Minifier
How to Use HTML Formatter & Validator
- Paste your code or data into the editor.
- Click Format to beautify or Validate to check for errors.
- Copy the cleaned output or review any issues found.
Frequently Asked Questions
What is HTML Formatter & Validator?
Format, validate, and beautify HTML code online for free. Fix indentation, check for mismatched tags, and clean up messy markup instantly in your browser.
What validation rules are applied?
Validation checks for correct syntax according to the language or data format specification. This includes balanced brackets, proper quoting, valid escape sequences, and structural integrity of the document.
Does formatting change the data?
No, formatting only affects whitespace, indentation, and line breaks. The actual data content and semantics remain identical, ensuring your code or configuration behaves exactly the same after formatting.
What indentation options are available?
You can choose between spaces and tabs, and configure the number of spaces per indent level (commonly 2 or 4). The formatter applies your chosen style consistently throughout the entire document.
Is HTML Formatter & Validator free to use?
Yes, formatting and validation are completely free. There are no usage caps, and no signup or account is ever required.
Is my data safe when using HTML Formatter & Validator?
Yes, your code and data stay on your device. All formatting and validation happens locally in the browser with no server communication.