JSON Formatter Online
Paste minified or messy JSON and get clean, indented output instantly — 2-space, 4-space, or tab indent. 100% in your browser.
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Format, validate, fix, explore paths, generate TypeScript & SQL — all in one
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Read Guide →JSON Formatter — Format, Beautify & Validate JSON Online
A JSON formatter (also called a JSON beautifier, JSON pretty-printer, or JSON viewer) adds indentation, line breaks, and consistent spacing to minified or compact JSON, making it instantly readable. Paste any JSON — a compressed API response, a log entry, a config file — and get back properly structured output with 2-space, 4-space, or tab indentation.
This formatter also validates JSON syntax and highlights the exact line and column of any error — trailing commas, unquoted keys, mismatched brackets — so you can fix issues fast without guessing. Everything runs 100% in your browser. No upload, no server, no account required.
Press ⌘+Enter (Mac) or Ctrl+Enter (Windows) to format instantly without clicking. Copy the result in one more keystroke.
Format JSON in One Step
Paste JSON
Drop in any JSON string — minified API response, a log entry, or a config file. Any size works.
Choose indent
Select 2 spaces, 4 spaces, or tabs. The formatter applies consistent indentation throughout.
Validate & format
Syntax errors are flagged instantly with exact line and column numbers. Valid JSON is formatted in milliseconds.
Copy or download
One-click copy to clipboard or download as a .json file. Nothing was sent to any server.
When Developers Format JSON
Debug API Responses
Expand a compressed API response to read its structure and find missing or unexpected fields quickly.
Config File Editing
Format package.json, tsconfig.json, appsettings.json before editing to avoid structural mistakes.
Log Inspection
Parse JSON log entries inline to read structured data without writing a script or using jq.
Code Review Prep
Format JSON fixtures or test data before committing to make diffs readable and reviewable.
Safe AI Debugging
Format JSON before pasting into ChatGPT or Claude, then mask sensitive fields with AI Schema Masker.
Pre-deploy Validation
Catch JSON syntax errors in config files or data files before they break a deployment.
Your JSON Never Leaves Your Browser
Most JSON formatters send your data to a server for processing. That means your API responses, config files, and JSON payloads — which may contain API keys, database credentials, personal data, or proprietary business logic — are transmitted over the internet to a third party.
This formatter is different. All formatting and validation runs in your browser using JavaScript. There is no backend server, no upload endpoint, and no analytics on what you paste. This makes it safe for:
Enterprise environments with data loss prevention (DLP) policies that block uploading sensitive data to external services. Production debugging where JSON payloads may contain live user data or credentials. Healthcare and fintech where HIPAA, GDPR, or SOC 2 compliance requires data to stay within controlled boundaries.
Common JSON Syntax Errors & How to Fix Them
The formatter catches these errors and highlights their exact location:
Trailing commas — JSON (unlike JavaScript) does not allow a comma after the last element: "roles": ["admin", "user",] is invalid. Remove the comma after "user".
Single quotes — JSON requires double quotes for both keys and string values. {'name': 'Alice'} is invalid. Use {"name": "Alice"} instead.
Unquoted keys — {name: "Alice"} is invalid JavaScript-style notation. JSON requires {"name": "Alice"}.
Comments — JSON does not support comments. Lines starting with // or /* */ will cause a parse error. Use .jsonc (JSON with Comments) for config files that need them — but strip comments before parsing as standard JSON.
Frequently Asked Questions
1What is the difference between JSON formatter and JSON beautifier?
2Does this JSON formatter upload my data?
3What is the difference between a JSON formatter and a JSON validator?
4Can I format JSON with custom indentation?
5How do I format a JSON API response?
6What errors does the formatter catch?
7Can I use the formatter offline?
8Is there a keyboard shortcut?
9How do I format JSON in JavaScript?
JSON.stringify(obj, null, 2) for 2-space indentation or JSON.stringify(obj, null, 4) for 4 spaces. To minify, use JSON.stringify(obj) with no space argument.10How do I format JSON in Python?
json.dumps(data, indent=2) for 2-space indentation. To write to a file: json.dump(data, file, indent=2). To parse JSON: json.loads(json_string) or json.load(file).Developer Guides
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