JSON Tools
Everything for JSON in one place: format and validate it, minify it, escape it into a string, and convert it to YAML, CSV, XML or TOML. All tools share one editor and hand content to each other, so you can format, fix and convert without pasting twice.
About JSON Tools
JSON is the most common payload a developer handles, so it gets the deepest set of tools. The formatter and validator share an error catalogue that recognises trailing commas, single quotes, unquoted keys, comments, smart quotes and truncated input, and fixes the safe ones for you.
Conversions are chained from any JSON tool through Next actions. Lenient mode accepts JSON5-style comments and trailing commas when you are working with config files rather than strict API payloads.
Frequently asked questions
What is the difference between the JSON Formatter and the JSON Validator?
Both parse the same way. The formatter focuses on readable output and shows errors when they occur; the validator produces a report — valid or not, where, why, and how to fix it — and is the better page to link from documentation.
Does Formattr support JSON5 or JSONC?
Yes, through lenient mode, which removes comments and trailing commas before parsing and tells you what it removed.
More categories
- Data Formatters & ConvertersFormat, validate and convert the data and configuration formats developers handle every day: JSON, YAML, XML, CSV, TOML and .env files. Every tool here keeps the same information and changes only its structure — pretty-printed for reading, minified for shipping, or converted for the next system. Everything runs in your browser, so API responses and customer records never leave your machine.
- Code FormattersFormat JavaScript, TypeScript, HTML, CSS, Markdown and more with the same engines your editor uses — Prettier, clang-format, gofmt and Ruff — without installing anything. Paste minified or messy code, get consistently formatted output, and minify it again when you need to ship. Code never leaves your browser.