File Converter

Convert between CSV, JSON, plain text and Base64 in your own browser. The file never leaves your computer - there is nothing to upload and nothing stored.

Your file stays on your computer. There is no upload on this page — the conversion runs in your browser, so nothing reaches our server and there is nothing stored to delete. It works offline, and it works on a file you would not send to a stranger.

From

Choose a file, or drop it here Or just paste into the box below

Out

What it does, and what it will not pretend to do

CSV to JSON uses the first row as the keys and gives you an array of objects. Quoted fields, commas inside quotes and doubled quotes are all handled.
JSON to CSV wants an array of objects. The columns are every key that appears anywhere, so rows with missing keys get empty cells rather than being dropped.
Base64 here is for text. Encoding a picture as Base64 works, but the result is a wall of characters rather than a file you can open — use the image converter for pictures.
No Word, PDF or Excel. Those need a rendering engine that would have to run on a server, which would mean uploading your file. It is left out on purpose rather than done badly.
Nested JSON flattens to a.b.c column names on the way to CSV, because a spreadsheet cell cannot hold an object.