CSV to JSON converter

Updated 28 September 2026

To convert CSV to JSON, drop the file and click Convert to JSON. You get back an array that holds one object per row, with the header row supplying the keys.

Spreadsheets and databases hand data out as CSV, while most web APIs, web apps and config files expect JSON. This tool moves data from the first format to the second without any manual editing.

Take a file whose header is id,zip,city and whose next line is 17,02134,Boston. That line becomes the object {"id": "17", "zip": "02134", "city": "Boston"} inside the array. We indent the output so people can read it and save it as UTF-8, and accented or non-Latin characters appear as themselves rather than as escape sequences.

Every value stays a string

Each value is written exactly as the CSV has it, wrapped in quotes. 17 turns into "17", and a blank cell turns into "". That is a deliberate choice. Guessing types would strip the zero from 02134, and nobody can tell from the text alone whether 1.000 means one or a thousand. If your application needs real numbers, convert those fields at the moment it reads the JSON.

The CSV files it understands

We find the separator by looking at the beginning of the file, so commas, semicolons, tabs and pipes all work, and .tsv files do too. Spreadsheet exports made with English settings and with European settings are both covered. Quoted fields that hold separators or line breaks come through intact, and a byte order mark at the very start is skipped. The file itself should be UTF-8.

The first line has to be the header. Without one, the first line of data turns into the keys, so add a header before converting.

Batches, pipelines and the API

Without an account, drop up to 5 files at once, each up to 50 MB, within 20 server jobs a day. A free account raises the batch to 10 files and the allowance to 50 jobs a day, and Pro handles batches of up to 500 files of up to 500 MB with no daily allowance. Download the JSON files separately or bundled in one ZIP.

For a system that writes a fresh export every day, the API can take over the routine: a free account includes 20 calls a day and Pro 1,000. The pipeline builder can also place this conversion after other steps, such as a row filter, and is free to try on up to 3 files.

Where the conversion runs

Everything happens on our servers in Germany, not in your browser. The upload is encrypted in transit, and we delete your files automatically within two hours.

How to turn a CSV into JSON

1. Drop one or more .csv files onto the page.
2. Click Convert to JSON.
3. Download the .json files one by one or as a ZIP.