Last updated: October 2026
Convert CSV to JSON online free — the honest version
Short answer: paste or drop a CSV file of any size and get clean, pretty-printed JSON in one click — no signup, no upload, no file-size cap. The converter runs 100% in your browser, handles quoted commas, line breaks inside fields, and escaped quotes, and auto-detects comma, semicolon, tab or pipe delimiters. Your data never leaves your device.
How it works
1. Paste CSV text into the box or drop a .csv file onto the dropzone above (tap to choose a file on your phone). 2. Choose your options: keep "First row is headers" on to get an array of named objects, or turn it off for a plain array of arrays. 3. Click Convert to JSON — then copy the result or download it as a .json file.
The parser follows the CSV format properly: quoted fields, escaped double-quotes (""), commas and line breaks inside quotes, and both LF and CRLF line endings all convert correctly. Output is standard JSON, pretty-printed with 2-space indentation.
Why there's no file size limit here
Most online CSV converters are a csv to json converter with a signup gate or a cap: upload your file to their server, and free conversions stop at around 1 MB or a few conversions per day. This one is different by design — because nothing is uploaded, there is nothing to meter. Your browser parses the file locally, so a 100,000-row export converts as easily as a 10-row one, with no account, no queue and no daily limit.
Frequently asked questions
What delimiter is detected?
The converter tries comma, semicolon, tab and pipe on the first line of your CSV and picks whichever produces the most columns. Commas, semicolons, tabs and pipes are all detected automatically. You can also force one with the delimiter dropdown.
What if my CSV has no headers?
Uncheck "First row is headers" and the converter outputs a plain array of arrays — one inner array per row — instead of objects. Missing cells in ragged rows become null.
Is there a file size limit?
No. There is no file-size cap and no row limit — the conversion runs entirely in your own browser, so a 100,000-row export converts as easily as a 10-row one. Rival converters that upload your file typically cap free files at 1 MB or a handful of conversions per day.
Is my data private?
Completely. Your CSV never leaves your browser — there is no upload and no server processing anything. You can even run this page offline after it loads.
What happens if rows have different numbers of columns?
Rows with fewer cells than the header get null for the missing values; extra cells beyond the header are ignored. The stats line under the output tells you the exact row × column count.
