JSON Formatter
Beautify, validate, query, and repair JSON in the browser
Use JSON Formatter free in your browser. Free online JSON formatter and toolkit. Beautify or minify JSON, validate with line errors, browse a collapsible tree, sort keys, escape strings, run JSONPath, validate against JSON Schema, and repair broken JSON — no signup.
What you can do with JSON Formatter
JSON Formatter on OnliKit is a free browser tool for everyday work — beautify, validate, query, and repair json in the browser. Use it when you need a quick result without installing software or creating an account.
- Beautify and minify JSON with 2-space, 4-space, or tab indentation.
- Validate JSON and see clear parse errors with line and column when available.
- Browse a collapsible tree view of nested objects and arrays.
- Sort object keys deeply, escape or unescape JSON strings, and run JSONPath queries.
- Validate JSON instances against a JSON Schema and inspect validation errors.
- Repair common broken JSON issues such as trailing commas, then re-validate.
Why use JSON Formatter?
Use this workspace when debugging API responses, cleaning config blobs, or checking payloads before you commit them. Everything runs in your browser so your data stays on the device.
Switch modes for tree browsing, JSONPath extraction, schema checks, and best-effort repair without opening a separate app for each task.
How to use JSON Formatter
- 01Paste JSON into the input box, or load the sample to explore the UI.
- 02Pick a mode — Format, Tree, Escape, JSONPath, Schema, or Repair.
- 03Run Beautify, Minify, query, validate, or repair depending on the mode.
- 04Copy or download the result when you are done.
Frequently asked questions
Does JSON formatting leave my computer?
No. Formatting, validation, JSONPath, schema checks, and repair all run in your browser. Nothing is uploaded to OnliKit servers.
Can I validate JSON against a schema?
Yes. Open Schema mode, paste your instance and a JSON Schema, then validate to see pass/fail and error paths.
What does Repair fix?
Repair uses best-effort fixes for common issues like trailing commas and similar syntax problems, then you can beautify or validate the cleaned JSON.
Is the JSON formatter free?
Yes. You can use every mode on OnliKit without creating an account.
Related tools
After you finish with JSON Formatter, try these related OnliKit tools — or browse all tools.
- JSON ParserParse, format, validate, and inspect JSON in a clean workspace
- JSON ↔ YAML / TOMLConvert between JSON, YAML, and TOML in one workspace
- Diff CheckerCompare two text blocks with inline red and green highlights
- JSON Diff CheckerCompare two JSON documents as formatted text or a collapsible diff tree
Also see more data tools.