Outils JSON

A complete JSON workbench in your browser

JSON is everywhere — API responses, config files, NoSQL exports, log entries. This page bundles the operations developers and analysts need every day:

Formater (pretty-print)

Turn a one-line minified blob or messy hand-written JSON into a clean, indented document. Choose 2 spaces, 4 spaces or a real tab character. Useful for reading API responses, sharing snippets in bug reports, or pasting into documentation.

Minifier

Strip every unnecessary character from JSON to ship the smallest possible payload. Typical savings are 20-40% on real-world data; on heavily indented configs the savings can hit 60%. The status bar shows the exact byte difference and percent saved.

Valider

Verify your JSON parses cleanly. On error, we display the engine's message plus a guessed line and column number with a 2-line snippet showing exactly where parsing broke. This works even in browsers and runtimes that no longer include positions in error messages — we figure it out ourselves.

JSON ↔ CSV

Convert an array of objects to CSV with one click. Nested objects are flattened with dot-notation (so {"user":{"name":"Alice"}} becomes a column user.name). Nested arrays are serialized as JSON strings inside their cells. Rows with different keys produce the union of all columns — missing fields become empty cells. The CSV → JSON direction handles quoted fields, embedded commas, and escaped quotes correctly (we use the battle-tested PapaParse library).

Confidentialité

Everything runs locally. Your JSON, your CSV, your secrets — none of it leaves the browser tab. The only network request is the one-time CDN load of PapaParse. We don't even see file sizes.

Cas d'utilisation courants

• Pretty-print an unreadable API response from curl.
• Minify a config file before embedding it in a script.
• Validate a JSON Schema document or LLM-generated structured output.
• Export a spreadsheet to JSON for use in a frontend app.
• Convert API results to CSV for analysis in Excel or Google Sheets.