Best free JSON formatter online
Format messy API responses, config files, and logs into readable JSON. Developer Friend runs entirely in your browser so your data never leaves your device.
Why use a JSON formatter?
JSON is the lingua franca of modern APIs, but minified or single-line JSON is hard to read in tickets, Slack, or the terminal. A good formatter adds indentation and line breaks so you can scan structure, spot missing commas, and compare payloads. Our tool also validates syntax and can minify when you need a smaller body for requests or storage.
Format, validate, and minify in one place
Format turns compact JSON into indented, human-readable text. Validate checks that your document parses correctly and surfaces errors with a clear message. Minify strips whitespace—useful before sending large bodies over the wire or embedding JSON in another format.
- Paste from clipboard or type directly
- No server round-trip; works offline after first load
- Pairs well with our JSON diff and tree viewer
Common JSON mistakes (and how to spot them)
Trailing commas after the last property, single quotes instead of double quotes, and unescaped newlines inside strings are frequent issues. A validator tells you where parsing failed so you can fix logs or copy-paste errors quickly. If you work with APIs, keeping a formatter tab open saves time on every debugging session.
JSON formatter vs. IDE plugins
IDEs format JSON well for files on disk. A browser formatter shines when you are pasting from Chrome DevTools, Postman, or production logs—you do not need a project open. Developer Friend is free, fast, and part of a larger set of developer tools online (encoding, timestamps, regex, and more).