Beautify, inspect, validate, and clean JSON payloads with instant error detection and collapsible tree views.
All formatting, parsing, decoding, and validation executes entirely within your browser using modern Web APIs and JavaScript. Your tokens, JSON payloads, regex inputs, and queries never leave your computer.
JSON (JavaScript Object Notation, RFC 8259) is the universal data interchange format for modern REST APIs, GraphQL endpoints, microservices, and configuration files. Complex or minified API responses can be difficult to read and debug when keys are packed into single-line strings.
DevRef's Online JSON Formatter transforms compressed or unformatted JSON into human-readable, indented structures with syntax highlighting. When syntax errors occur—such as missing quotes, trailing commas, or unbalanced brackets—the editor immediately pinpoints the exact line and character so you can fix your payload without guessing.
No. All formatting, validation, and tree parsing happens 100% in your browser using local JavaScript. No JSON content is transmitted, recorded, or cached externally.
The most common syntax violations are: trailing commas after the last array item or object property, single quotes ('...') instead of double quotes ("..."), and unquoted object keys.
Yes. The editor is built on the high-performance Monaco Editor engine and handles multi-megabyte JSON payloads with smooth scrolling and rapid rendering.
Formatted (beautified) JSON includes newlines and spaces for human readability during development. Minified JSON removes all unnecessary whitespace to minimize network transfer size.
Learn how to properly escape special characters, quotes, and newlines in JSON strings.
Techniques for semantic JSON diffing ignoring key order and formatting differences.
Query and filter deep JSON structures using expressions like $.store.book[*].author.
Compare two JSON documents side-by-side to highlight additions, deletions, and edits.