Convert CSV to JSON
Free · no signup · no watermark · runs in your browser · batch up to 20 files
Drop your CSV files here
or click to choose — up to 20 at once
Select CSV fileThis runs entirely in your browser. The file never leaves your machine and nothing is uploaded. Need test files? Try our free sample files.
Spreadsheets export CSV; APIs want JSON. The conversion itself is trivial and the edge cases are not: fields containing commas, quotes inside quoted fields, embedded newlines, and the question of whether 007 is a number or a string. This handles all four.
This conversion runs entirely in your browser. The file is never uploaded, which makes it instant, private and usable on work files you would not want to send to a stranger's server.
How to convert CSV to JSON
- Drop your CSV files onto the box above, or click it to choose from your computer. Up to 20 at once.
- The conversion starts as soon as the file is read — there is nothing to configure.
- Download each converted file, or pick them up one by one from the list.
What changes when you convert CSV to JSON
CSV carries no type information — every value is text. Numbers and booleans that look like numbers and booleans are converted to real types, which is almost always what you want and occasionally not, for example with leading-zero identifiers and postal codes.
CSV and JSON compared
| CSV | JSON | |
|---|---|---|
| Full name | Comma-Separated Values | JavaScript Object Notation |
| Extension | .csv | .json |
| MIME type | text/csv | application/json |
CSV: The lowest common denominator for tabular data: every spreadsheet and database reads it. It carries no types, so everything arrives as text, and quoting rules are where most import bugs live.
JSON: The default interchange format for web APIs. Supports nesting, arrays and real types, which CSV does not, so converting between the two means deciding how to flatten or rebuild structure.
Frequently asked questions
How do I convert CSV to JSON?
Drop your .csv file onto the box on this page and the .json file is ready to download in a second or two. There is no signup, no email, no watermark and no file limit beyond what your browser can hold in memory.
Is this CSV to JSON converter free?
Yes, completely, with no account, no trial and no watermark on the output. We are a consultancy and these tools exist because we needed them ourselves; there is nothing to buy on this page.
Are my files uploaded anywhere?
No. This conversion runs entirely in your browser using JavaScript, so the file never leaves your computer. You can disconnect from the network after the page loads and it will still work.
Will converting to JSON reduce the quality?
CSV carries no type information — every value is text. Numbers and booleans that look like numbers and booleans are converted to real types, which is almost always what you want and occasionally not, for example with leading-zero identifiers and postal codes.
Can I convert several CSV files at once?
Yes, up to 20 files in one go. Drop them all onto the box together and each one appears in the results list with its own download button.
Found a problem, or something that could be better? We read every message and we fix things quickly.
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