Nested JSON ⇄ CSV (Flatten)
Flatten nested JSON objects and arrays into flat CSV columns like address.city, or rebuild nested JSON from a flat CSV. Supports files up to 200MB.
Or convert a file directly — supports files up to 200MB
Drag & drop a file here, or click to browse
Processed in the background, so the page stays responsive even for huge files
How to use this tool
Unlike a plain JSON → CSV converter, this tool handles deeply nestedobjects and arrays by flattening each field into a dotted column name, e.g. address.city or hobbies.0. Switch to CSV → Nested JSON to reverse the process and rebuild the original object structure from those dotted headers. Great for exporting API responses or MongoDB documents into a spreadsheet-friendly format.
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