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JSON to CSV Converter — Flatten Nested Objects in Your Browser
Convert JSON arrays to RFC 4180 CSV or TSV with dotted nested keys, then reverse CSV back to JSON. Preview rows and download locally — nothing is uploaded.
- Mobile Friendly
- Accessibility Tested
- SEO Optimized
- Fast Loading
- Responsive
Version 1.0.0 · Last reviewed
How it worksShow guide
Introduction
Paste an array of objects (or a single object) and export comma, semicolon, tab, or pipe-separated rows. Nested keys become dotted headers unless you keep them as JSON cells. The reverse path rebuilds records, optionally nesting dotted headers. Parsing stays on your device.
Step-by-step
- Choose JSON → CSV or CSV → JSON
- Pick a delimiter and flattening option
- Copy or download after the preview looks right
Worked example
Flattening yields a header user.name and a single data row Ada. Rebuilding with nest on restores { user: { name: "Ada" } }.
Use cases
- Turn an API JSON array into a spreadsheet
- Rebuild JSON from an exported CSV with quoted commas
- Preview the first rows before you download
Frequently asked questions
Does my data leave the browser?
No. Conversion runs locally. Download uses a blob in this tab.
How are nested objects handled?
Dot flattening walks objects and arrays (user.city, tags.0). JSON-cell mode stringifies nested values into one column instead.
Are there size limits?
Yes — hundreds of thousands of characters, 5,000 rows, and 200 columns — so a huge paste cannot freeze the tab.
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