A free online tool to format, validate, repair, beautify, and minify your JSON data. Instantly pretty-print JSON, auto-fix common syntax issues with a JSON repair engine, check for errors with a powerful linter, and compress it for production use.

Compress and format your JS, CSS, and HTML code online. A powerful tool to minify JavaScript, compress CSS, and beautify HTML, XML, and JSON to reduce file size and improve readability.

Test, debug, and validate your regular expressions online in real-time. Supports JavaScript and PCRE-like syntax with flags, highlighting, and detailed match information.

Easily compare two text files to find the differences. Our online diff checker highlights additions and deletions, allowing you to see changes side-by-side or in a unified view.

Compare fractions fast and precisely with rational-number math. Supports different denominators via cross-multiplication or common denominator (LCM), simplifying before comparison, mixed numbers to improper conversion, and fraction–decimal–percentage/ratio/scientific notation interoperability. Clear steps, examples, and internationalization. New: fraction comparison print — clean, print-friendly pages for steps and results, plus one‑click print and save to PDF.