JSON Forge — Offline JSON Toolkit

JSON Forge is a free, private, browser-based JSON toolkit for developers, data wranglers and curious tinkerers.

Three tools, one tidy workspace

Inspect

• Validate JSON with helpful error messages and line/column hints.
• Format or minify your JSON in one click.
• Browse a collapsible JSON tree and search paths or values.
• Copy JSON paths, text, or download your document.

Compare

• Compare two JSON documents by structure.
• See added, removed and changed values with exact JSON paths.
• Ignore object property ordering while preserving array ordering.
• Export a readable text diff report.

Convert

• Export arrays of JSON objects as CSV, TSV or semicolon-separated text.
• Import CSV/TSV and receive an array of JSON objects.
• Handles escaped quotes and multiline CSV fields.
• Warns you about lossy conversions and protects spreadsheet formula-like values by default.

Built for privacy

• 100% offline once loaded — no uploads, login or server processing.
• No external scripts, tracking, analytics or cookies.
• Files are processed entirely in your browser.
• Works on desktop and mobile.

How to start: Press Run tool above. Try the Sample button, then explore the Inspect, Compare and Convert tabs.

Limitations: JSON-to-CSV requires an array of objects; CSV-to-JSON keeps values as strings. Opened files are limited to 5 MiB, conversions to 15,000 CSV rows, displayed comparisons to 250 differences and rendered trees to 1,400 nodes. CSV conversion can be lossy.

Free and open source under the MIT License.

Version 1.0.0