# JSON formatter, validator & tree — in your browser, no upload

> Format, validate and explore JSON in a tree view in your browser. No upload — parsing runs locally, so config and API payloads stay on your device.

Pretty-print messy JSON, catch syntax errors, and browse the structure as a collapsible tree. Everything is parsed in your browser, so the data never leaves your device.

JSON is the format developers stare at all day — API responses, config files, log lines — and it is easy to get a wall of unindented text or a parse error with no clue where. A formatter with a tree view turns that into something readable and navigable.

Beautify to standard indentation, minify for transport, and use the validator to jump straight to the character that broke parsing. The tree view is the fastest way to find a nested field in a large payload without scrolling.

When you need to reshape or query data rather than just read it, use the Data Zone tools; to turn JSON into typed models, see JSON to types.

## How to

1. **Paste your JSON.** Paste or type the JSON you want to format or check.
2. **Format or validate.** Beautify with proper indentation, or see exactly where a syntax error is.
3. **Explore the tree.** Expand and collapse objects and arrays to navigate large payloads.
4. **Copy.** Copy the formatted JSON back out for your code or config.

## FAQ

### Why won't my JSON parse?

Common causes are trailing commas, single quotes instead of double, unquoted keys, or a stray comment — the validator points to the offending position.

### Can it handle large files?

Yes, within your device's memory. Parsing and the tree view run locally, so speed depends on your machine rather than a server.

### Does it minify as well as format?

Yes — you can compact JSON to a single line as well as pretty-print it with indentation.

### Is my JSON uploaded?

No. Parsing, validation, and formatting happen in your browser tab; sensitive config and API payloads stay on your device.


## Related tools

- [Base64](https://www.safepaper.app/dev/base64)
- [Format swap](https://www.safepaper.app/data/csv-to-json)
- [Regex playground](https://www.safepaper.app/dev/regex-playground)
- [JSON → TypeScript](https://www.safepaper.app/data/json-to-typescript)

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Canonical HTML: https://www.safepaper.app/dev/json-toolkit
Markdown: https://www.safepaper.app/dev/json-toolkit.md

There is no upload endpoint — your files are processed in this browser tab. Open your network tab and check.