How to Use the JSON Formatter
Paste your raw or minified JSON into the input box on the left, then click Format / Beautify to get a nicely indented, human-readable version. Use Minify to compress it for production use. Any errors in your JSON are detected and shown with a precise error message.
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write and easy for machines to parse and generate. JSON is used by virtually every modern web API to exchange data between clients and servers.
When Should You Format JSON?
- Debugging API responses — Raw API responses are often minified and hard to read.
- Code reviews — Properly formatted JSON is easier to inspect for correctness.
- Config files — Configuration files like
package.jsonshould be formatted for readability. - Learning — Seeing JSON in a clean, indented format helps beginners understand data structure.
When Should You Minify JSON?
Minifying JSON removes all whitespace and newlines, making the file smaller. This is useful when sending JSON over a network (API responses, config payloads) where every byte counts for performance.
Common JSON Errors and How to Fix Them
| Error | Cause | Fix |
|---|---|---|
| Unexpected token | Missing comma or bracket | Check for missing , between items |
| Unexpected end of JSON | Unclosed bracket or brace | Make sure all { and [ are closed |
| Expected property name | Single quotes instead of double | Use double quotes for keys: "name" |
| Trailing comma | Extra comma at end of array/object | Remove the last comma before } or ] |
Frequently Asked Questions
Is my JSON data sent to a server?
No. All processing happens in your browser. Your JSON data never leaves your device.
Can I format very large JSON files?
Yes, up to a practical browser memory limit. For files larger than a few MB, performance may vary by device.