CSV to JSON
Turn CSV rows into JSON objects keyed by column name. Nothing is uploaded.
Drop CSV files here
Converted on your device. Files are never uploaded.
Up to 20 files at a time.
APIs, web apps and scripts usually want JSON, while spreadsheets export CSV. FormatJet reads your CSV with Papa Parse, works out the separator and writes each row as a JSON object keyed by its column names, with numbers kept as numbers. The conversion happens in your browser, so the data never leaves your device.
About the formats
CSVCSV file
CSV stores a table as plain text, one row per line with commas between the values. Spreadsheets, databases and almost every data tool can read and write it.
JSONJSON file
JSON is the text format web APIs and apps use to exchange data: objects, lists, text, numbers and true or false values, nested as deep as needed.
Converted with Data converters (Papa Parse, yaml, fast-xml-parser), Data converters on Workers.
Questions
What does each CSV row become in the JSON?
With “First row holds the column names” on, as it is by default, each row becomes an object whose keys are the column names. Turn it off and every row becomes a plain list of values instead.
Will ZIP codes and long IDs lose their leading zeros?
No. “Store numbers and true/false as values” turns plain numbers into JSON numbers, but values like 02134, digit strings longer than 15 digits and figures written as 1,234 stay strings, so nothing is altered.
My CSV uses semicolons. Does that work?
Yes. The separator is detected from the file, whether it’s a comma, semicolon, tab or another common one, and quoted values that contain separators or line breaks are read correctly.
What if some columns have no header?
Blank column names become column_1, column_2 and so on, and a repeated name gets _2 added, so every key in the JSON is unique.
Can I get compact JSON on one line?
Yes. Untick “Indent the JSON” in Options. It’s on by default, which lays the JSON out over several lines so it’s easy to read.
CSV to JSON with the API
The conversion API opens later this year.
curl https://api.formatjet.com/v1/convert?to=json \
-H "Authorization: Bearer fj_test_…" \
-F file=@input.csv -o output.json