How it works
The CSV to JSON Converter parses a CSV (comma-separated values) string and transforms it into a well-structured JSON array of objects — where the first row is treated as column headers and each subsequent row becomes a JSON object with those keys.
CSV and JSON are the two most common data interchange formats. CSV is used by spreadsheets, databases, and export tools. JSON is used by APIs, JavaScript applications, and NoSQL databases. Converting between them is a constant workflow in data engineering, front-end development, and content migration.
How to use it: paste your CSV data (with a header row). The tool detects the delimiter automatically (comma, tab, semicolon, or pipe) and produces a pretty-printed JSON array. Options: use the first row as object keys (default), output a flat array of arrays instead, or produce a JSON Lines (JSONL) format (one JSON object per line, no wrapping array).
Edge cases handled: quoted fields containing commas or line breaks, escaped quotes within fields, fields with Unicode characters, numbers and booleans detected and typed correctly (so "42" becomes the number 42, not the string "42"), and empty fields becoming null.
Privacy: CSVs often contain sensitive data — customer records, financial data, internal metrics. The conversion runs entirely in your browser with no server upload.
Frequently Asked Questions
- Yes. The tool checks for commas, tabs, semicolons, and pipes in order and uses the delimiter that appears most consistently. You can override the auto-detected delimiter manually if needed.
- RFC 4180 quoting is fully supported: fields enclosed in double quotes may contain commas, newlines, and escaped double quotes (represented as two consecutive quotes: "").
- Yes. The converter detects numeric strings and converts them to JSON numbers. 'true' and 'false' are converted to JSON booleans. 'null' and empty fields become JSON null.
- Sparse rows (fewer columns than the header) are padded with null for missing values. Extra columns beyond the header are included under auto-generated numeric keys (_col4, _col5, etc.).