JSON Formatter & Validator
Format, validate, and explore JSON with a collapsible tree view. Runs entirely in your browser.
Batch workspace
Format multiple files locally in one run.
How to use the JSON Formatter
Paste code or file
Paste your raw JSON text or upload directly.
Configure options
Choose indentation, dialect, or formatting preferences.
Format & export
Click format, then copy, download, or inspect in tree view.
What is a JSON Formatter?
Format, validate, and explore JSON with a collapsible tree view. Runs entirely in your browser. This tool re-indents and organizes code according to standard style conventions while checking for syntax validity. Everything executes 100% inside your browser, guaranteeing zero latency and complete privacy for API keys, user tokens, and confidential database schemas.
A JSON formatter is one of the highest-traffic developer utilities on the web because APIs, configs, and logs ship minified payloads by default. This page focuses on fast local formatting with precise parse errors — line and column when available — plus a collapsible tree for exploring nested structures without uploading anything. Use Sort keys when you need stable diffs, and pair this tool with the JSON Validator or JSON Schema cheat sheet when you need structural guarantees beyond syntax.
Common errors and fixes
Unexpected token } in JSON
Remove a trailing comma before the closing brace, or add the missing property that should come before it.
Unexpected end of JSON input
Your payload is truncated — check for an unclosed string, array, or object.
Unexpected non-whitespace character after JSON
Paste a single JSON value. Extra text after the root object/array is invalid.
Expected property name or '}' in JSON
Object keys must be double-quoted strings. Single quotes are not valid JSON.
Options Explained
| Option | Description |
|---|---|
| Indent | Controls how many spaces (or a tab) are used for each nesting level. |
| Sort keys alphabetically | Reorders object keys A-Z. Useful for diffing two JSON payloads. |
Frequently Asked Questions
Is my JSON sent to a server?
No. Formatting and validation run entirely inside your browser using JavaScript. Your data never leaves your machine.
Why do I get 'Unexpected token' errors?
This usually means a trailing comma, a missing quote around a key, or a missing comma between properties. Check the line and column shown in the error.
Can I format very large JSON files?
Files under 5MB format directly in the editor. Larger files are processed in a background worker and offered as a download so the page never freezes.
Does this tool validate JSON Schema?
No, this validates that your JSON is syntactically correct. For schema validation, check our JSON Schema cheat sheet for the vocabulary reference.
Can I sort my JSON keys alphabetically?
Yes, enable 'Sort keys alphabetically' in the options panel before formatting.
Free Developer Cheat Sheet
Download a handy, printable reference guide for JSON Formatter syntax and best practices.
Download Free Cheat Sheet