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CSV to JSON Converter
Paste CSV or upload a file and get a clean JSON array. The header row becomes the keys.
Runs in your browser. Your data is never sent to a server.
How to use the CSV to JSON
Paste or upload CSV
Paste CSV text or drop a .csv file. The delimiter, comma, semicolon, tab or pipe, is detected automatically.
Set the options
Use the first row as keys, turn numbers and true/false into real JSON types and choose objects or arrays.
Copy or download JSON
Copy the JSON or download it as a .json file, pretty-printed or minified.
Why use this tool
CSV is how spreadsheets, databases and analytics tools export tables, while web apps and APIs expect JSON. This converter reads the CSV the way the standard defines it, including quoted fields with commas and line breaks inside them, and turns each row into a JSON object keyed by the header.
Type detection turns 42 into a number, true into a boolean and empty cells into null, so the JSON is ready to use without extra parsing. Leave it off if you need every value kept exactly as text, for example ZIP codes or IDs with leading zeros.
Frequently asked questions
How do I convert CSV to JSON?
Paste the CSV or upload the file. With First row as keys switched on, each row becomes an object; copy the JSON or download it.
Can I convert Excel to JSON?
Save the sheet as CSV in Excel (File, Save As, CSV UTF-8), then convert that file here.
What if my CSV uses semicolons or tabs?
The delimiter is detected automatically. You can also choose it yourself if a file is unusual.
How do I convert CSV to JSON in Python?
json.dump(list(csv.DictReader(open("data.csv", newline=""))), out, indent=2). DictReader uses the first row as keys, just like this tool.
Are my files uploaded to a server?
No. formatmath converts files with code that runs inside your browser. Your files are never uploaded, stored or seen by us.
Is it free?
Yes. There is no watermark and no daily limit. An account is optional and only keeps a history of your conversions.