JSON Formatter & Validator

Format and Validate JSON Online

This free JSON formatter takes raw, minified, or messy JSON and turns it into clean, properly indented text that is easy to read and debug. Paste your data, and the tool reformats it instantly, adding consistent spacing and line breaks so nested objects and arrays line up clearly. It also validates the structure, flagging common problems such as a missing comma, an unclosed bracket, or a trailing comma that breaks parsing.

Developers, testers, and students use a tool like this every day when inspecting API responses, configuration files, or log output. Reading a single long line of JSON is difficult, but indented output makes the hierarchy obvious at a glance.

How to Use It

Copy the JSON you want to check and paste it into the input area. The formatter beautifies valid input and points out where invalid input fails so you can fix the syntax. You can switch between a readable, indented view and a compact, minified version that strips whitespace to shrink file size for transmission.

All processing happens in your browser, so your data is not uploaded or stored. The tool works the same on mobile and desktop, and no signup is required.