How to use
- Paste a JSON array of objects (a single object also works).
- Pick the delimiter — comma for most tools, semicolon for Excel in regions that use a decimal comma.
- Tick "Add BOM" if the file will be opened in Excel and contains non-English text.
- Copy the CSV or download it as a .csv file.
Options explained
- Nested objects
- Flattened into dotted column names: {"address":{"city":"Paris"}} becomes the column address.city.
- Arrays inside rows
- Written as JSON text in a single cell, for example [1,2,3], so no data is lost.
- Missing keys
- Columns are the union of keys from all rows, in first-seen order; rows without a key get an empty cell.
- BOM
- A byte-order mark tells Excel the file is UTF-8. Without it Excel on Windows shows accented and Chinese characters as garbage.
Example
JSON:
[{"id":1,"name":"Ada","address":{"city":"London"}},{"id":2,"name":"Grace, Jr.","tags":["navy","cobol"]}]CSV:
id,name,address.city,tags
1,Ada,London,
2,"Grace, Jr.",,"[""navy"",""cobol""]"Frequently asked questions
Why does Excel put everything in one column?
In some locales Excel expects semicolons as the separator. Choose Semicolon as the delimiter, or open the file through Data → From Text/CSV and pick the delimiter there.
Why are my characters garbled in Excel?
Excel assumes a legacy encoding unless the file starts with a UTF-8 BOM. Tick "Add BOM (for Excel)" and download again.
How are commas and quotes inside values handled?
Following RFC 4180, values containing commas, quotes or line breaks are wrapped in double quotes, and quotes inside them are doubled.
Is there a row limit?
No fixed limit. Tens of thousands of rows convert in a second or two in the browser; Excel itself stops at 1,048,576 rows.
Privacy
This tool runs entirely in your browser. Your files and text are processed on your device and are never uploaded to our servers.