JSON Formatter Pro - Viewer with a Collapsible Tree

Auto-format and validate JSON & API responses instantly. Syntax highlighting, tree view, dark mode. Data never leaves your browser.

JSON Formatter Pro automatically detects and formats JSON in your browser. Open any URL that returns JSON or an API response, and it instantly transforms raw JSON into a clean, syntax-highlighted, collapsible tree view — no copy-pasting into web tools needed. FORMATTING & VALIDATION: • Auto-Detection — Automatically detects and formats JSON responses and .json files • JSON Beautifier — Pretty-print minified JSON with proper indentation • JSON Validator — Catch syntax errors with clear, actionable error messages • Raw & Parsed Toggle — Switch between raw JSON text and formatted tree view instantly DEVELOPER TOOLS: • Syntax Highlighting — Color-coded keys, strings, numbers, booleans, and null values • Collapsible Tree View — Expand and collapse any node to navigate large JSON documents • Clickable URLs — Links in JSON values are automatically clickable • Dark Mode — True dark theme designed for long coding sessions • Copy to Clipboard — Copy any node or the entire formatted JSON with one click Runs 100% in your browser. No external servers, no data collection, no tracking, no ads. Fully open-source.