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