Fast by default
Static site built with Astro. No sluggish ad-heavy layouts. 1 MB JSON parses in under 200 ms on modern devices.
Format code. Keep it private. Learn the format.
Beautify, minify, and validate JSON — with XML and HTML coming soon. All parsing runs on your device. No uploads. No tracking of your inputs.
Available tools
JSON
Beautify, minify, and validate JSON. Syntax errors with line and column. Sort keys alphabetically. Upload files up to 5 MB.
Open →XML
Format XML documents with CDATA, processing-instruction, and comment preservation. Validate via the browser's native parser.
Open →HTML
HTML5 beautifier that understands void elements and preserves pre, script, and style contents.
Private by design
All parsing and formatting runs on your device. Your code is never sent to our servers.
More than a tool
Each format page ships with short guides and a glossary of related terms so you can learn while you work.
Accessible & mobile-friendly
Keyboard shortcuts, a proper dark mode, and a layout that works on your phone during a late-night debug session.
Featured guides
What Is JSON? A Plain-English Guide to JavaScript Object Notation
JSON is the lingua franca of web APIs. This guide walks through its syntax, its data types, the trade-offs that shaped it, and the small gotchas that trip up newcomers.
Read →The 10 Most Common JSON Syntax Errors (and How to Fix Them)
Most JSON parse errors come from a handful of mistakes. This reference covers the ten offenders we see most, what their error messages look like, and how to fix each one quickly.
Read →JSON vs YAML: When to Use Which Format
JSON and YAML solve overlapping problems but optimise for different users. This guide compares their syntax, strengths, and failure modes so you can pick the right one without regret.
Read →JSON Schema Basics: Validating Data with Confidence
JSON Schema is how you describe, document, and enforce the shape of a JSON document. This primer walks through the core keywords and the workflow that makes them pay off.
Read →