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Convert CSV ↔ JSON

Convert tabular data between CSV and JSON. Choose a delimiter and download the result. Free, no sign-up, right in your browser.

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Questions about this tool

How does this tool work: Convert CSV ↔ JSON?

Free, no sign-up, right in your browser. Choose direction and delimiter, paste text or load a file. Convert and download. Quotes and multiline cells are supported.

Are leading zeros in CSV cells preserved?

Yes. CSV cells are copied to JSON as strings: 01234 stays "01234". JSON to CSV accepts flat objects; null and missing values become empty cells. The conversion is therefore not fully type-preserving in both directions.

What inputs, outputs and limits apply?

Input: CSV with a header row or a JSON array of flat objects; UTF-8. Output: JSON array or CSV with a header row; file download. Limits: At most 500,000 characters, 2 MB per file, 10,000 data rows and 100 columns. CSV cells become JSON strings, preserving leading zeros. JSON null and missing values become empty CSV cells. Nested values and duplicate headers are rejected.

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Instructions, example and file limits

Formats, inputs and limits

Input: CSV with a header row or a JSON array of flat objects; UTF-8
Output: JSON array or CSV with a header row; file download
Limits & notes: At most 500,000 characters, 2 MB per file, 10,000 data rows and 100 columns. CSV cells become JSON strings, preserving leading zeros. JSON null and missing values become empty CSV cells. Nested values and duplicate headers are rejected.