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Open ToolJSON Formatter & Validator (Beautify, Minify & Validate)
Beautify messy JSON payloads, validate syntax errors with exact line/column indicators, and minify for production.
⚡ Automated API Data Pipe
Automate JSON Validation & API Webhook Forwarding
Eliminate manual JSON formatting in browser tabs. Automate payload extraction, schema validation, and desktop forwarding.
How to Format and Validate JSON
1
Paste Your Raw JSON Payload
Paste any JSON string or load our sample JSON structure into the editor.
2
Format or Minify with One Click
Choose 2-space beautification, 4-space indentation, or compact 1-line minification.
3
Review Diagnostics and Export
Verify syntax status, inspect byte metrics, and copy or download the formatted JSON file.
Common JSON Syntax Errors & How to Fix Them
JSON (JavaScript Object Notation) has strict syntax rules defined by RFC 8259. Here are the most frequent causes of invalid JSON errors:
| Common Syntax Error | Invalid Example | Valid Correction | Rule Explanation |
|---|---|---|---|
| Trailing Commas | {"name": "App",} | {"name": "App"} | JSON strictly forbids trailing commas after the last property or array item. |
| Single Quotes | {'key': 'value'} | {"key": "value"} | All string literals and property keys must use double quotes ("). |
| Unquoted Property Names | {status: true} | {"status": true} | Unlike JavaScript objects, JSON requires explicit double quotes around all keys. |
| Undefined / Nan Values | {"val": undefined} | {"val": null} | JSON only supports strings, numbers, booleans, arrays, objects, and null. |
Key Features of Our JSON Utility
Precise Syntax Error Locator
Pinpoints exact error messages and positions when parsing malformed JSON payloads.
Custom Indentation Modes
Supports both standard 2-space and 4-space code styles for optimal readability.
One-Click Minifier
Strips unnecessary whitespace and line breaks to minimize payload size for network requests.
100% Client-Side Privacy
Sensitive API keys, auth tokens, and private data in your JSON never leave your browser.
Frequently Asked Questions
Clear answers about using this tool and automating workflows with RunMacro.
Why does JSON require double quotes around property keys?
The official JSON standard (RFC 8259) strictly mandates double quotes ("key") for all object properties. Single quotes or unquoted keys cause syntax errors.
Are trailing commas allowed in JSON?
No. Unlike modern JavaScript, JSON syntax prohibits trailing commas after the last item in an array or object.
Can RunMacro parse and trigger actions based on JSON API responses?
Yes! RunMacro Web Automation blocks can execute HTTP requests, parse JSON response fields, and pass data dynamically into form fields or Excel sheets.
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