JSON Wrench is a fast, client-side JSON tool for developers. Format, beautify, validate, repair, and minify JSON directly in your browser — no data is ever sent to a server.
Pretty-print minified or compact JSON into a readable, indented format with full syntax highlighting for keys, strings, numbers, booleans, and null values.
Real-time JSON validator that catches syntax errors as you type. Unlike other validators, JSON Wrench explains each error in plain English — trailing commas, single quotes, unquoted keys, missing brackets, and more.
Auto-repair broken or invalid JSON with one click. JSON Wrench fixes the actual broken lines — not just where the parser got confused — and shows a precise diff of every change made so you know exactly what was wrong.
Compress JSON to the smallest possible size for APIs and storage. View and inspect formatted JSON with syntax highlighting. Share any JSON via a compressed URL — no account or sign-up required.
Most JSON formatters tell you “SyntaxError: Unexpected token” and leave you to figure out the rest. JSON Wrench identifies 12 specific error types — trailing commas, single quotes, unquoted keys, HTML responses, NaN values, duplicate keys, and more — and explains exactly what caused the error and how to fix it. The one-click repair shows a visual diff so you can verify every change before using the output.