JSON to CSV Converter – Turn JSON into CSV Instantly

What does the JSON to CSV converter do?

This free online tool takes JSON — usually an array of objects like [{"name": "Alice", "age": 30}, ...] — and turns it into RFC 4180 compliant CSV. The union of all object keys across every record becomes the header row, and each object becomes a data row. Missing keys become empty cells, so nothing gets dropped.

Nested objects are flattened with dot notation when the Flatten nested objects toggle is on. So {"address": {"city": "London", "zip": "SW1"}} becomes two columns: address.city and address.zip. Arrays inside a record are joined with a pipe character by default, so you don't lose data when a field holds a list.

Everything runs locally in your browser. Your JSON never leaves your device — no server upload, no logging, no tracking. Close the tab and it's gone.

How to convert JSON to CSV — step by step

1. Paste your JSON: Drop an array of objects, an array of arrays, a single object, or an object wrapping a single array into the input box.
2. Choose the output delimiter: Comma is the standard CSV format. Use semicolon for European locales, tab for TSV, or pipe if your target system expects it.
3. Set the toggles: Add a header row, flatten nested objects, quote fields per RFC 4180, and trim whitespace from string values.
4. Click Convert to CSV: The tool parses your JSON and shows the CSV instantly, with row and column counts.
5. Copy or download: Use the Copy CSV button or download the result as a real .csv file ready for Excel, Google Sheets, or any database import.

Shortcut: Press Ctrl + Enter (or Cmd + Enter on Mac) inside the input box to convert instantly.

Example: before and after

Input (JSON array of objects)

[
  {"Name": "Alice", "Age": 30, "City": "New York", "Active": true},
  {"Name": "Bob", "Age": 25, "City": "London", "Active": false}
]

Output CSV (comma-delimited, header on)

Name,Age,City,Active
Alice,30,New York,true
Bob,25,London,false

Nested objects, flattened

[
  {"id": 1, "user": {"name": "Alice", "email": "a@x.com"}},
  {"id": 2, "user": {"name": "Bob", "email": "b@x.com"}}
]

With flattening on, this becomes:

id,user.name,user.email
1,Alice,a@x.com
2,Bob,b@x.com

If any value contains a comma, quote, or newline, it's automatically wrapped in double quotes with internal quotes escaped as "".

Supported JSON shapes

When would you need to convert JSON to CSV?

Tips and best practices

• Use an array of objects when possible. Named keys produce a much more useful CSV than positional arrays, because the header row carries meaning.
• Watch out for inconsistent keys. If some objects have {"name": ...} and others have {"Name": ...}, they'll become separate columns with empty cells for the mismatched rows. Normalise your keys first for a cleaner result.
• Flatten only when you need flat data. If a downstream system can handle dotted keys like user.name, keep flattening on. If you'd rather keep the nested object as a stringified JSON cell, turn flattening off.
• Use semicolon output for European Excel. Excel in many EU locales expects semicolons to delimit fields. If opening the CSV puts everything in column A, try semicolon output.
• Keep quoting on. It's the difference between a file that imports cleanly and one where columns shift because a field contained a comma.
• Watch out for leading zeros. Excel strips them from numbers on import. If you have codes like 007, quote those fields or prefix with an apostrophe after import.
• Need the reverse? Try the CSV to JSON tool to go the other way.
• Need to beautify the JSON first? Run it through the JSON Formatter.

Related tools you might need

• CSV to JSON — reverse of this tool.
• JSON Formatter — prettify and validate JSON before converting.
• JSON Validator — check JSON syntax and locate errors.
• JSON Minifier — shrink JSON payloads.
• CSV to Text — flatten CSV to plain text.
• Text to CSV — convert plain text to CSV.
• Whitespace Cleaner — clean up messy CSV before converting.

Privacy, accuracy, and limits

Privacy: Nothing you paste into this converter is sent to a server. The whole JSON parser and CSV writer is JavaScript running in your browser tab. There is no upload, no analytics event containing your data, and no server-side log.

Accuracy: The CSV writer follows RFC 4180 — any field containing the delimiter, a double quote, or a newline is wrapped in double quotes, and internal quotes are doubled. Nested objects are flattened with dot notation. Arrays are joined with a pipe by default.

Limits: There is no hard limit on input size. Since everything runs in-browser, the practical limit is your device's memory. A JSON array with tens of thousands of records converts in well under a second. Very large pastes (multiple megabytes) may take a moment. A built-in safety guard warns you before generating output that could freeze the tab.

Frequently asked questions