UtilTools

JSON to CSV

Flatten nested JSON into a spreadsheet-ready table.

JSON to CSV converts an array of objects into CSV, flattening nested objects into dotted column names and handling arrays either as joined values or as expanded columns. Quoting follows RFC 4180, so values containing commas, quotes and newlines survive intact in Excel. Conversion runs in your browser, so the data stays with you.

Loading JSON to CSV…

Runs entirely on your device. No file or text you enter here is uploaded. How to verify it.

How to use JSON to CSV

  1. Paste JSON, or open a .json file.
  2. Choose the delimiter and how to flatten nested values.
  3. Preview the table and download the CSV.

Questions about JSON to CSV

How are nested objects handled?
Flattened with dotted paths: {"user":{"name":"Ada"}} becomes a column called user.name. Nesting depth is unlimited, and the column set is the union of every key found across all rows so nothing is dropped.
What about arrays inside a record?
Two options: join them into one cell with a separator, or expand them into indexed columns such as tags.0 and tags.1. The right choice depends on whether you will filter on them.
Will Excel open it correctly?
Yes, with the correct quoting and an optional UTF-8 byte order mark, which is what stops Excel mangling accented characters. Semicolon delimiter is available for locales where Excel expects it.
What is the largest file it can convert?
Files of tens of megabytes convert without complaint. The whole document is parsed in memory, so somewhere past roughly 100 MB you meet the browser limit rather than a limit this tool sets.
Can I open the result in Google Sheets or Numbers?
Yes. Download the CSV and import it, or paste the text straight into a sheet. Both read UTF-8 properly, so the byte order mark that keeps Excel happy can be left switched off for them.
Is JSON to CSV really free, with no limits?
Yes. There is no account, no daily cap, no file-size tier and no watermark, because there is no server cost to recover. The site is funded by clearly disclosed partner recommendations on the Partners page, never by metering the tools.
Are my files or text uploaded when I use JSON to CSV?
No. Everything is processed by JavaScript running in your browser, on your device. You can verify it: open your browser's developer tools, switch to the Network tab, and use the tool. You will see no request carrying your data — because there is nowhere for it to go.