gratistools.be
Sign in

CSV Diff

Paste two CSV files. Pick a key column to match rows by ID, or compare them in order.

Compared on your device. Nothing is uploaded unless you save.

Differences

Paste the original on the left and the changed version on the right. Differences appear here as you type.

Match rows by a key column

With Match rows by: Row position, row 5 on the left is compared with row 5 on the right. That's fine when both files are sorted the same way, but one inserted row shifts everything after it. Choose an ID column instead (customer number, SKU, email…) and rows are matched by that value, regardless of order. You then get three clear lists: rows only in the original (removed), rows only in the new file (added), and rows present in both where one or more cells changed — with those cells highlighted and the old value shown next to the new one.

Columns are matched by header name, so a file with the same columns in a different order compares correctly, and added or removed columns are listed separately.

Delimiters and Excel exports

The delimiter is detected automatically: comma, semicolon, tab or pipe. Excel in many European locales (including Belgian, Dutch, French and German) saves "CSV" with semicolons because the comma is the decimal separator — that's handled. Quoted fields containing delimiters, quotes ("") or line breaks follow the standard CSV rules (RFC 4180).

Tips

  • Keep Trim cell spaces on to ignore padding that some exports add.
  • If the tool warns about duplicate keys, the column you picked isn't unique. Pick another, or compare by position.
  • Numbers are compared as text, so 10.5 and 10.50 are reported as different — that is usually what an export check needs.

Is my data uploaded?

No. The comparison runs in your browser, so nothing you add is sent to gratistools.be. It only leaves your device if you sign in and press Save, which stores that one comparison in your account until you delete it. See the privacy page for details.