CSV to JSON Converter
Convert CSV or TSV to JSON locally. Preserve leading zeros, long identifiers and text values; catch malformed rows before copying or downloading.
1. Add your data
Processed only in this browser. No upload or storage.
First row = column names. 00123, true, null and empty values are not inferred as other types. No duplicate-header or missing-cell repairs.
Supported formats and limits
UTF-8; comma / semicolon / Tab; LF / CRLF; quoted separators, newlines and doubled quotes. Blank lines are not skipped. No Excel workbooks, Big5 or lone CR.
1 MiB input, 10,000 records, 200 columns, 200,000 data cells; 8 MiB output and a 5-second timeout. Spaces around header names are preserved.
2. Get your JSON
Paste your data or load a sample, then convert.
Next steps (data is not transferred): JSON Formatter · JSON → TypeScript
How to use this tool
Paste CSV or choose a UTF-8 file, select its separator, and convert. The first row supplies unique column names. Every value stays a string; copy or download the complete JSON array.
When not to use it
Not an Excel workbook reader or a data validator. No automatic type inference, header repair or missing-cell filling. Use your organization’s approved workflow for sensitive records.
Read the guide →