Question 1

How do I convert JSON to CSV online?

Accepted Answer

Paste your JSON array or upload a .json file into the input panel. Pick your delimiter (comma, semicolon, tab, or pipe), toggle the header row or flatten nesting if needed, and the CSV output is generated instantly in the right panel. Click Copy or Download to save the result.

Question 2

Can I also convert CSV back to JSON?

Accepted Answer

Yes. Click the "CSV → JSON" tab at the top of the converter, or use the Swap button to reverse direction. The tool handles quoted fields, escaped quotes, and quoted newlines per RFC 4180. It also auto-detects data types, so "true" becomes a boolean, "42" becomes a number, and empty cells become null.

Question 3

How does the JSON flattener handle nested objects?

Accepted Answer

When "Flatten nested" is on, nested keys are joined with dot notation. For example, {"user": {"address": {"city": "NYC"}}} becomes the column header user.address.city. When converting CSV back to JSON with "Unflatten keys" enabled, those dot-notation headers rebuild the original nested structure. This makes round-trip conversion lossless.

Question 4

What happens to arrays inside my JSON?

Accepted Answer

Arrays embedded in values (like tags or categories) are joined with a pipe character so no data is lost. For example, ["vip", "beta-tester"] becomes vip|beta-tester in the CSV. When converting back to JSON, pipe-separated values are automatically split back into real arrays.

Question 5

Is my data safe when using this JSON to CSV converter?

Accepted Answer

Yes, completely. All conversion runs in your browser using client-side JavaScript. Your JSON and CSV data never leaves your device, never touches our servers, and is never logged, stored, or transmitted anywhere. You can verify this by opening DevTools and checking the Network tab while converting.

Question 6

What delimiters does the CSV converter support?

Accepted Answer

Four delimiters are supported: comma (standard CSV), semicolon (common in European locales where comma is the decimal separator), tab (TSV format), and pipe. Pick whichever matches your downstream tool, whether that's Excel, Google Sheets, PostgreSQL COPY, or a custom parser.

Question 7

Will strings with commas, quotes, or newlines break my CSV?

Accepted Answer

No. The converter is RFC 4180 compliant. Any cell containing a delimiter, quote, or newline is automatically wrapped in double quotes, and any internal quotes are escaped by doubling them. So a value like She said "hi" becomes "She said ""hi""" in the output, which parses back perfectly.

Question 8

Is there a file size limit?

Accepted Answer

There is no hard limit, but since conversion runs in your browser, performance depends on your device. Files up to a few megabytes convert in milliseconds. For JSON files with hundreds of thousands of rows, expect a brief pause while parsing. We recommend Chrome, Firefox, Safari, or any modern browser.

Question 9

Can I use the CSV output directly in Google Sheets or Excel?

Accepted Answer

Yes. The downloaded .csv file opens directly in Google Sheets, Microsoft Excel, LibreOffice Calc, and Apple Numbers. For Google Sheets, use File > Import and select the CSV. For Excel, double-click the file or use Data > From Text/CSV for full delimiter control.

Question 10

How do I convert a JSON array to CSV with a header row?

Accepted Answer

The header row is included by default. The converter reads the keys from the first JSON object and uses them as column headers. Every subsequent object is written as a row in the same column order. You can toggle the header row off in the options if your target system does not need it.

Question 11

How do I flatten nested JSON to CSV online?

Accepted Answer

Turn on the Flatten nested option. Nested keys are joined with dot notation so {"user":{"city":"NYC"}} becomes the column user.city. Deeply nested objects and arrays are flattened up to a practical depth for spreadsheet use.

Question 12

How does access work for this JSON converter?

Accepted Answer

The JSON to CSV converter runs directly in the browser. Future versions may include ads or paid plan features, but the conversion workflow is built to stay fast and practical for everyday data work.

JSON to CSV Converter Online

How to convert JSON to CSV online

Paste or upload your JSON

Pick your delimiter and options

Copy or download the result

Built for developers who ship

100% client side

Instant conversion

RFC 4180 compliant

Nested JSON ready

Bidirectional swap

Export workflow

Frequently asked questions

CSV to JSON Converter

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