Online code formatters
This category holds 8 online code formatters that turn an unreadable dump into something you can actually review: format and validate JSON, beautify HTML, indent SQL queries, render Markdown, minify CSS and JavaScript, and convert between YAML, XML and JSON. They all point at the syntax error instead of merely failing.
The natural audience is developers in the middle of a code review or debugging an integration: the minified API response you have to read, the forty-line SQL query inherited from another team, the Kubernetes manifest that needs to become JSON, or the stylesheet worth compressing before deployment. The pages also explain the rules of each format, from why JSON rejects trailing commas to why YAML indentation changes the meaning of the document.
Tools in this category
JSON Formatter
Format, validate and minify JSON documents
YAML/JSON Converter
Convert between YAML and JSON formats
Markdown Preview
Render Markdown to HTML in real time
XML/JSON Converter
Convert between XML and JSON formats
SQL Formatter
Format and beautify SQL queries
CSS Minifier
Minify and compress CSS code
HTML Beautifier
Format and beautify HTML code
JavaScript Minifier
Minify and compress JavaScript code
Frequently asked questions
Does formatting change how the code behaves?
No. Formatters only touch whitespace, line breaks and indentation; the logic, identifiers and values are untouched. The conceptual exception is JavaScript minification, which also shortens local variable names and removes dead code, although the result remains functionally equivalent.
What is the difference between minifying and compressing?
Minifying transforms the source by removing what the browser does not need. Compressing with gzip or Brotli reduces the bytes in transit without altering the content, and the server does it. The two are complementary: you minify first and compress afterwards, and together they can take a 100 KB stylesheet down to around 6 KB.
Can I use these formatters with production data?
Yes. Processing is entirely client-side, so whatever you paste is neither transmitted nor stored. Even so, for very large payloads of tens of megabytes a command line tool that streams the input rather than loading it all into memory is a better fit.