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Convert CSV to JSON

Convert CSV to JSON in seconds. Free, no signup, no watermark, no file-size limit. Your file is processed in your browser and never uploaded.

At a glance

Source
CSV
Target
JSON
Where it runs
Your browser
Cost
Free, unlimited
Account
Not needed
CSV

Converter

CSV to JSON

On device

Drop one or more comma separated values files.

or select comma separated values

Your file never leaves this browser

    The details

    What happens when you convert between data formats

    One table, one row per line, values separated by commas. The most importable format there is. The data is parsed into a structure and written back out in the target format — a flat table becomes nested objects, or vice versa. The result is a javascript object notation. the default way machines exchange structured data, produced entirely inside your browser.

    What survives

    • Every value
    • The relationships, wherever the target format can express them

    What changes

    • The shape of the data, which is the point of the conversion
    • The order of keys, which is not guaranteed to be preserved

    Where it goes wrong

    • JSON to CSV only makes sense for a flat list of objects — anything nested is flattened or lost
    • XML has no standard for a list of items, so the same file can parse into different structures in different tools

    Why anyone would do this

    Every system wants a different shape, and reshaping by hand is where mistakes happen.

    About the format

    One table, one row per line, values separated by commas.

    Plain text. Each line is a record, each value is separated by a delimiter, and the first line is usually a header row.

    Where it is good
    • Almost every system on earth can import it
    • Plain text, so you can read and edit it directly
    • Perfectly suited to genuine tables
    Where it falls short
    • No formatting, no multiple sheets, no formulas
    • Commas and newlines inside values need careful quoting
    • Encoding problems appear the moment a spreadsheet exports it
    You will find it on
    Data analysts, developers, every import button ever built

    The thing people miss

    A CSV exported by Excel on Windows is often UTF-8 with a byte order mark, which makes the first column name read as "Name".

    About the target

    JavaScript Object Notation.

    Text made of objects, arrays, strings, numbers, booleans and null, with a syntax borrowed from JavaScript but with no code in it.

    • Readable as well as parseable
    • Maps almost exactly onto objects in every major language
    • Strict about its types, so mistakes surface immediately

    Real jobs

    What people are actually doing with CSV

    Getting data out of a system that only exports plain text

    Importing a list into a website, a CRM or a bank portal

    Turning a spreadsheet into something a script can read

    Specification

    The details, in one table

    Source formatCSV — Comma separated values
    Target formatJSON — JSON data
    Typical source size1 KB – 100 MB
    RunsIn your browser
    Account neededNo
    WatermarkNone
    File extension.csv → .json

    How to

    CSV to JSON, step by step

    1. 01

      Add your comma separated values

      Drag the file onto the drop zone, or tap to browse. Only one file is needed.

    2. 02

      Choose the JSON settings

      Set the JSON-specific options — everything happens locally, so the speed is your device, not a queue.

    3. 03

      Download the result

      The finished JSON downloads to your device. Nothing is uploaded and nothing is retained.

    Also available

    CSV converts into

    PDFPDF documentHTMLHTML documentTXTPlain textXLSXExcel workbook

    Questions

    CSV conversion questions

    What actually happens to my CSV file when I convert it to JSON?

    The data is parsed into a structure and written back out in the target format — a flat table becomes nested objects, or vice versa. So the CSV file is unpacked, the content is laid out, and the result is written out as JSON. Every value survives unchanged.

    Will converting CSV to JSON reduce the quality?

    For this particular conversion, not in the way you would expect. Every value — the CSV content is not re-encoded in a lossy way. The only thing that changes is the format it is stored in.

    Is my CSV file uploaded to a server?

    No. This CSV to JSON conversion runs as JavaScript inside your browser tab. The file is read from your device and the result is written back to your device, so there is no upload step, no file-size limit and no copy of your CSV file on any server.

    Do I need an account or will there be a watermark?

    Neither. There is no sign-up step, no email capture and no watermark on the output. The only limits are the ones your own device imposes.

    What is the most common mistake people make when converting CSV to JSON?

    JSON to CSV only makes sense for a flat list of objects — anything nested is flattened or lost

    Why would somebody convert CSV to JSON at all?

    Every system wants a different shape, and reshaping by hand is where mistakes happen. In short: getting data out of a system that only exports plain text

    Something most people do not know about CSV?

    A CSV exported by Excel on Windows is often UTF-8 with a byte order mark, which makes the first column name read as "Name".