JSON Formatter & Validator

JSON (JavaScript Object Notation) is the most widely used data format in modern software development. REST APIs return JSON, configuration files are written in JSON, logs are structured as JSON, and databases store JSON documents. But JSON often arrives minified — stripped of all whitespace to reduce size — making it nearly impossible to read at a glance.

This tool pretty-prints JSON with configurable indentation so you can read and understand its structure immediately. Paste a minified API response and instantly see nested objects and arrays laid out clearly. Choose 2 spaces, 4 spaces, or tabs depending on your preference or project conventions.

The validator catches common JSON errors and reports the exact location of the problem. JSON is stricter than JavaScript object literals: property names must be double-quoted, trailing commas are not allowed, and undefined values are not permitted. If you copy JSON from a browser console or a code snippet, there may be subtle syntax issues that this tool will surface immediately.

The minify function removes all unnecessary whitespace to produce the smallest possible representation of your data. Use this before storing JSON in a database, sending it in an HTTP request body, or embedding it in source code where compactness matters more than readability. All operations run entirely in your browser; nothing is sent to our servers.