CSV ↔ JSON Converter
Convert CSV data to JSON array and JSON back to CSV.
CSV Input
JSON Output
About the CSV ↔ JSON Converter
Convert CSV data into a JSON array, or turn JSON back into CSV. Spreadsheets export CSV and APIs speak JSON, so this conversion sits between almost every data import and the code that has to consume it.
How to use it
- 1 Paste CSV to convert it to JSON, or paste JSON to get CSV.
- 2 Confirm the delimiter and whether the first row is a header.
- 3 Review the converted output.
- 4 Copy or download the result.
What it does
- Bidirectional CSV and JSON conversion
- Configurable delimiter: comma, semicolon or tab
- Header row detection
- Correct handling of quoted fields containing commas and newlines
- Download the converted file
Frequently asked questions
Is my data uploaded?
No. Every calculation happens locally in your browser using JavaScript. Nothing you paste is uploaded, logged, or stored on a server, which makes the tool safe to use with production data, credentials, and customer records.
How are commas inside a field handled?
By quoting. A field containing a comma, a newline, or a quote character is wrapped in double quotes, and any literal quote inside it is doubled. The parser here follows RFC 4180, so quoted fields survive the round trip intact — a naive split on commas would not.
Why does my CSV use semicolons instead of commas?
Regional settings. In locales where the comma is the decimal separator, Excel exports semicolon-delimited files instead. Set the delimiter to semicolon and it will parse correctly.
Can it convert nested JSON to CSV?
CSV is a flat, tabular format with no concept of nesting, so deeply nested objects and arrays cannot be represented directly. Nested values are flattened where possible; for genuinely hierarchical data, keep it as JSON.
Are long numbers preserved exactly?
Watch out here. JSON numbers are IEEE-754 doubles, so integers beyond 2^53 lose precision — this bites with IDs and phone numbers. If a column contains long numeric identifiers, treat them as strings rather than numbers.