CSV to JSON converter.
Paste or open a CSV file, handle quoted commas and new lines, choose delimiters, then download clean JSON without uploads.
Handles quoted commas, embedded line breaks and escaped quotes. Text values such as IDs with leading zeros stay as text.
Runs locally. Limit: 2 million input characters, 10,000 data rows and 250 columns. CSV values remain strings by design, preserving leading zeros and avoiding accidental number or date conversions.
How to use this tool
- Paste your CSV data or choose a CSV/TSV file from your computer.
- Set the delimiter and choose whether the first row contains column names.
- Review the parsed row count and JSON output, then copy or download the .json file.
Good to know
All values remain strings to preserve IDs such as 00123. Duplicate column headings, missing headings and inconsistent row lengths are reported instead of silently changing the data.
This utility processes its content locally in your browser. No usage counter is required while public tools are free and unlimited. As with any online tool, avoid entering sensitive information on devices you do not trust.
Why CSV conversion is trickier than it looks
CSV can contain a comma inside a field: a contact name like "Doe, Jane" is one value, not two columns. A quoted cell can also contain a line break or an escaped double quote. Replacing every comma with a JSON separator will quietly scramble these records.
The converter recognizes quoted fields, double-quote escaping, and comma, semicolon or tab separators. If a row has a different number of columns, it shows an error rather than guessing where the data belongs.
Keep IDs as strings
Values such as 00123 or 000045 look numeric, but may actually be reference numbers, postal codes or account identifiers. Turning them into numbers removes their leading zeros. This tool keeps every CSV cell as text by design.
If your destination requires numeric values or dates, make those conversions explicitly in your own application after reviewing the source. That is safer than a converter silently guessing data types.
Headers, arrays and file limits
With First row contains column names selected, the result is an array of JSON objects. Without headers, the result is an array of arrays. Duplicate or empty column names are rejected because they would otherwise lose information in an object.
You can paste text or open a local CSV/TSV file. File reading and conversion happen in your browser. For large datasets, use a spreadsheet or script with a tested import process instead of putting everything in one text box.
Questions about csv to json converter
Does the converter accept commas inside quoted cells?
Yes. Quoted commas, embedded newlines and doubled quotes are handled. Unclosed quotes and inconsistent column counts produce errors.
Why did 00123 stay in quotes in the JSON?
Because it may be an identifier rather than a quantity. Keeping values as strings prevents losing leading zeros or accidentally changing dates.
Can I convert TSV or semicolon-separated data?
Yes. Choose the corresponding separator in the dropdown. You can also open a .tsv file locally.