JSON formatter & validator — beautify or minify
Paste JSON to validate it, pretty-print with indentation, or minify to one line for transport. API responses squashed into a single row and config files with a stray comma — clear error positions beat guessing in the dark.
Private · Fast · Free
Strict JSON forbids comments, trailing commas, and single-quoted keys. Copying from JavaScript objects causes most failures.
Pretty mode helps humans; minify saves bytes or fits length limits — neither changes meaning when the JSON is valid.
When validation fails, look next to the reported line: missing quote, extra comma, single quotes.
How to use
- Paste JSON text
- Validate or beautify to see errors
- Minify when you need a compact payload
- Copy the result
What formatting gives you
- Inspect structure without opening an IDE.
- Errors point near the break — good for learning and fixes.
- Toggle beautify/minify quickly.
Scenarios
- One-line gateway JSON responses
- Config snippet from chat without VS Code
- Pretty JSON for docs or tickets
Tips
- Validate before beautify — invalid JSON will not format meaningfully.
- Strip `undefined` and functions when copying from browser consoles.
- Huge JSON may lag on phones; trim to the failing section.
Contrast
| Input | Output | Note |
|---|---|---|
| {"a":1,} | Validation error (trailing comma) | Classic mistake |
| Single-line JSON | Indented tree | Easier to read |
JSON FAQ
- JSON5 with comments?
- This page expects standard JSON. Remove comments and trailing commas first.
- Will key order change?
- Output follows parsed structure; do not rely on key order for semantics.
- Big integers?
- Very large numbers may hit JS number limits. Use specialized tools for financial precision.