Paste JSON or CSV to convert between the two — conversion runs locally in your browser, with nothing uploaded.
How it works
- Flatten nested objects turns
{"meta": {"born": 1815}}into ameta.borncolumn — without it, nested objects can't be represented in flat CSV at all. - Multiple delimiters are supported: comma (standard), semicolon (common in European locales where comma is the decimal separator), tab (TSV), and pipe.
- Quoted fields containing commas, quotes, or newlines are handled correctly in both directions.
- Upload a
.jsonor.csvfile instead of pasting, and download the converted result as a file — everything happens locally in your browser.
Convert JSON to CSV and CSV to JSON in your browser — with delimiter options and nested-field handling. Your data never leaves your device, so it's safe for sensitive files.
Frequently asked questions
Does my data get uploaded?
No. The conversion runs entirely in JavaScript on your device, which makes it safe for confidential or personal data — nothing is transmitted to any server.
How are nested JSON objects handled?
Nested keys are flattened into dotted column names (for example user.name), so complex JSON still maps cleanly to a flat CSV table.
Can I choose the delimiter?
Yes — you can switch between comma, semicolon and tab delimiters to match Excel locales or other tools that expect a specific separator.
What if my CSV has commas inside values?
Values containing commas, quotes or line breaks are properly quoted and escaped per the CSV standard, so they round-trip correctly back to JSON.
Why JSON and CSV feel so different
CSV grew around flat rows and columns, while JSON can naturally represent nested objects and arrays. Converting between them is easy only when the JSON structure maps cleanly to a table.
The hidden difficulty is nesting
A customer object containing an address object has hierarchy; a CSV row does not. Converters must flatten, stringify or otherwise decide how nested values should fit into cells.