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JSON Validator

Validate JSON instantly in your browser with precise line and column error reporting. Supports JSON Lines batch checking. Free, private, no upload.

All processing happens locally in your browser. Files are never uploaded.

Introduction

JSON Validator checks whether your JSON document is syntactically correct and points directly at the line and column of the first error. It also detects JSON Lines input where every line is its own JSON value and reports each fragment separately. Everything runs locally in your browser, so no data is ever uploaded.

Features

  • Real-time validation as you type or paste
  • Precise line and column error reporting
  • JSON Lines / multi-fragment batch checking
  • Clear valid or invalid conclusion
  • Fully local processing, no uploads

How to use

  1. 1Paste your JSON into the editor.
  2. 2The tool validates it automatically; click Validate to re-run.
  3. 3Read the green success alert or the red error alert with line and column.
  4. 4Fix the reported error and re-validate until it passes.

Frequently asked questions

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