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JSON ↔ CSV Converter

Convert JSON arrays to CSV and back. Custom delimiter, flatten nested objects, auto-detect types. Runs 100% in your browser.

All tools Browser-only

JSON (array of objects)

CSV

Delimiter: First row is header Flatten nested objects (key.subkey) Quote all values

Convert between JSON and CSV — runs 100% in your browser. Your data never leaves the page. Useful for exporting to Excel, importing to DB, or sharing with teammates.

When to convert JSON ↔ CSV

Export API data: API returns JSON, your boss/client needs Excel/CSV — convert fast, no code needed.
Import into Google Sheets / Excel: pasting CSV is easier than parsing JSON.
Database migration: dump JSON from MongoDB → CSV for MySQL/PostgreSQL import.
Data cleaning: convert back and forth to inspect structure.
Sharing datasets: CSV is smaller and opens in any text editor.

Features

Auto-convert: type JSON on the left, CSV appears on the right after 200ms.
Flatten nested objects: {"user":{"name":"a"}} → column user.name.
Custom delimiter: comma (default), semicolon (European Excel), tab, pipe.
Quote all values: forces every cell to be wrapped in " — safe for fields with commas or newlines.
Auto type parsing: CSV → JSON automatically converts "123" → 123, "true" → true.
Download .json / .csv: click ⬇ to save the file.

CSV gotchas

European Excel uses semicolon ; instead of comma — good for data with decimal commas.
Cells with commas / newlines: the tool wraps them in " automatically (RFC 4180).
Cells with quotes: doubled to "" per RFC 4180.
BOM for Excel: if non-ASCII characters look wrong, re-save the file with UTF-8 + BOM in a text editor.

Who this is for

Fullstack/backend/devops engineers — debug JWT, format JSON/SQL, parse cURL, compute CIDR subnets, draft Mermaid diagrams, write conventional commits… Daily toolkit alongside your terminal and editor.

FAQ

Is my pasted code/token sent anywhere?

No. All TopDev dev tools run 100% client-side — JWT, SQL, JSON, cURL, regex… process in-browser. Disconnect to verify. Safe for internal tokens, production DB queries, API keys.

Does it work offline / install as a PWA?

Tools work offline after the first load. Installable PWA is on the roadmap — for now you can bookmark and use without internet.

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