CSV to JSON
CSV to JSON. Transform, inspect and copy your data. Your files stay on this device. Processing happens in your browser.
Enable JavaScript to use the tools. Files are processed in your browser.
How to convert CSV to JSON
Paste CSV text or open a .csv or .tsv file.
Leave the delimiter on automatic, or pick comma, semicolon or tab.
Press Convert to JSON and copy or download the result.
Header row and output shape
With First row is a header ticked, each following row becomes an object whose keys are the header names, which is the format most APIs and JavaScript code expect. Empty header cells are named column1, column2 and so on. Untick it to get an array of arrays instead, which keeps the exact grid of cells.
Quotes, commas and line breaks
The parser follows RFC 4180, the common CSV convention. Fields wrapped in double quotes may contain commas, semicolons and even line breaks, and a doubled quote inside a quoted field stands for one quote character. A UTF-8 byte-order mark at the start of the file, which Excel adds, is removed automatically. Automatic detection tries comma, semicolon, tab and pipe on up to 20 parsed rows and prefers a consistent multi-column structure. If it chooses incorrectly, select the delimiter manually.
Numbers and booleans
CSV has no data types, so by default every value stays a string. Tick Convert numbers and true/false to turn values such as 42, 3.5, true and null into JSON numbers, booleans and null. Values with leading zeros, such as postal codes or phone numbers like 02134, stay as text so that the zeros are not lost.
Privacy
The input is processed in this browser, without sending it to a conversion server. Pasted UTF-8 text and imported files are limited to 10 MiB each; complex data may fail sooner because memory and parser limits also apply. Page and script loading, advertising or analytics requests are separate; see Privacy. Downloaded results remain on your device.
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Frequently asked questions
Which delimiter does Excel use?
It depends on your regional settings. In many European locales Excel saves CSV with semicolons; automatic detection handles both.
Why are all my numbers in quotes?
Type conversion is off by default. Tick Convert numbers and true/false.
Can it read a CSV with line breaks inside cells?
Yes, as long as those cells are wrapped in double quotes, as Excel and Google Sheets do.
Is my file uploaded?
This converter does not upload the selected file or input for processing. That does not mean the website makes no network requests; see Privacy for page, advertising and analytics traffic.
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