JSON Formatter & Validator
Prettify, validate, sort keys, and compress JSON payloads client-side
What is JSON and Why Validate It?
JSON (JavaScript Object Notation) is the universal de-facto data serialization format across modern web APIs, microservices, and databases like PostgreSQL (JSONB) and MongoDB. However, raw API responses or minified log outputs are virtually impossible for human engineers to read, debug, or inspect without structural formatting.
A single missing comma, misplaced quotation mark, or unescaped newline can invalidate an entire configuration file or crash an API pipeline. This utility uses native browser parsing engine to pinpoint syntax errors with exact column and line numbers.
Common JSON Syntax Errors
- • Trailing Commas: Placing a comma after the last item in an array or object (`[1, 2, 3,]`) is invalid in strict JSON.
- • Single Quotes: JSON keys and string values must strictly use double quotes (`"key"`), not single quotes (`'key'`).
- • Unquoted Keys: Object keys like `{name: "John"}` must be formatted as `{"name": "John"}`.
- • Undefined & Functions: JSON does not support `undefined`, `NaN`, or JavaScript functions.
Privacy Guarantee
Many online formatting utilities transmit your clipboard contents to remote backend servers for telemetry or analytics logging. This poses extreme security risks for developers working with proprietary customer data, JWT authorization tokens, or internal API keys.
This tool runs 100% locally in your web browser. Disconnecting your internet connection will not interrupt its capability.