Free CSV and Excel tools

9 tools to open, convert, split, merge and clean CSV, Excel and JSON files. Every one is free, with no sign-up, no watermark and no daily limit.

Every one runs in your browser, so the file never leaves your device.

Open

Large CSV viewer
Open a spreadsheet too big for Excel and look through it.
Runs on your device; nothing uploaded

Convert

CSV to JSON
Turn a spreadsheet export into JSON, one object per row.
Runs on your device; nothing uploaded
JSON to CSV
Turn a list of JSON objects into a spreadsheet-ready CSV.
Runs on your device; nothing uploaded
Excel-safe CSV
Rewrite a CSV so Excel opens it with the right characters and columns.
Runs on your device; nothing uploaded
CSV to Excel
Turn a CSV into a real .xlsx workbook that opens without import steps.
Runs on your device; nothing uploaded
Excel to CSV
Save a worksheet from an .xlsx, .xls or .ods file as plain CSV.
Runs on your device; nothing uploaded

Edit

Guides

Reference pages with measured numbers.

Why Excel removes leading zeros and changes CSV data
The seven changes Excel silently makes when it opens a CSV file, with examples, and the import method that prevents every one of them.

Questions

Are these CSV and Excel tools free?

Yes. All 9 are free, with no sign-up and no daily limit on how many files you process, and the site adds no watermark of its own.

Are my files uploaded?

No. Every tool reads the file into your device's memory, processes it there and lets your browser save the result. Nothing is sent to WholeFiles or to anyone else.

How big a file can I use?

Files of a few hundred megabytes work on a computer. The Large CSV viewer opens files of four or five gigabytes, because it only draws the rows on screen.

Do they work on a phone?

Yes, in any current browser on Android or iPhone, with nothing to install. Very large files are easier on a computer, which has more memory.