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Code Formatter for JSON, XML, HTML & CSS

Validate and beautify JSON, XML and common markup in your browser.

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DATA & CODE WORKSPACE

Code Formatter for JSON, XML, HTML & CSS

Convert or format text locally in your browser. No file is uploaded to a ToolMosaic server.

Private by design

Values remain text. For downloadable CSV files, do not open data from untrusted sources in a spreadsheet without reviewing cells that begin with spreadsheet formula characters.

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About the Code Formatter for JSON, XML, HTML & CSS

Format common data and markup text—JSON, XML, HTML and CSS—directly in your browser, with immediate error messages for invalid JSON or XML.

Formula or method

JSON is parsed and output with two-space indentation. XML is parsed for correct nesting and reindented for element-only content. HTML is normalized by the browser HTML parser. CSS receives basic indentation around braces and semicolons.

Worked example

Paste {"active":true,"count":3} and choose JSON to display each key and value on its own line. XML mode highlights invalid element structure by returning a parse error.

How to use the tool

Start with the example values above, then replace each input with your own figures. The results update immediately. Review the units, denominators, and assumptions before using any number in an important decision.

Assumptions and limitations

This is not a full JavaScript, TypeScript, SQL or HTML code beautifier. Browser HTML parsing may normalize or repair markup, and formatting XML with mixed content can affect whitespace. Always review formatted output before replacing source code.

Frequently asked questions

Does code formatting change program behavior?

JSON whitespace has no effect on JSON data, but HTML/XML/CSS formatting may normalize syntax or whitespace. Review a diff and test before deploying modified code.

Privacy and support

Your inputs are processed locally in your browser. ToolMosaic does not upload or store the values you enter in this tool. Our tools are free, and we appreciate your support.