🧾 JSON Formatter
Pretty-print, minify, and validate JSON in a tap — tidy up API responses and Android config files and catch syntax errors on the spot. It all runs in your browser, so nothing is uploaded or stored.
🧾 Format, Minify & Validate JSON
What is a JSON Formatter?
JSON is the format most Android apps and web APIs use to exchange data. A JSON formatter re-indents a cramped or one-line response into a clean, nested layout you can actually read, minifies it back down when you need a compact payload, and validates it so malformed input is caught before it breaks your app.
Everything happens locally in your browser using the built-in parser — nothing is uploaded or stored — so it's safe to paste responses containing keys or personal data. Choose a 2- or 4-space indent, or hit Validate to pinpoint exactly where a stray comma or quote is tripping up the parser.
❓ Frequently Asked Questions
What does a JSON formatter do?
It takes raw JSON and re-indents it into a readable, pretty-printed layout so you can scan nested structures at a glance. It can also minify JSON — stripping every unnecessary space and newline to shrink payloads — and validate it, telling you exactly where the syntax breaks.
Is my JSON uploaded to a server?
No. Formatting, minifying, and validation all run entirely in your browser using the native JSON parser — your data never leaves your device and nothing is stored. That makes it safe to paste API responses that contain tokens or personal data.
Why is my JSON invalid?
Common culprits are trailing commas, single quotes instead of double quotes, unquoted keys, comments (JSON doesn't allow them), and unescaped characters inside strings. Use the Validate button — the error message points to where the parser gave up so you can fix it quickly.
Will formatting change my numbers or keys?
No. The formatter checks your JSON with the browser's parser, then re-spaces your original text, so every number and string is copied exactly as written. It warns when the program reading the JSON may change it: an integer past 9,007,199,254,740,991 (JavaScript rounds it, so send long IDs as strings), a number too large for a double such as 1e400, or a duplicate key (RFC 8259 says names within an object SHOULD be unique, and most parsers keep only the last value).
When should I minify versus format JSON?
Format (pretty-print) while you're reading or debugging, so the structure is easy to follow. Minify when you're shipping — a compact single-line payload is smaller over the network and is what you'd embed in an Android app's assets or send in an API request.