Someone sends you an updated version of a spreadsheet and asks what changed. Scrolling both files side by side and hoping to spot the differences is slow and unreliable, especially once a sheet runs to hundreds of rows. A diff does the spotting for you.
The short version: add the original and the updated file, choose how rows should be matched, and read off what was added, removed and changed. The compare tool runs on your device, so nothing is uploaded.
Matching rows is the part that decides everything
The hard part of comparing two tables is not spotting changed cells, it is knowing which row in file A corresponds to which row in file B. Get that wrong and a single inserted row at the top makes every row below it look “changed.”
There are two ways to match, and picking the right one is most of the job.
By position lines the files up row for row: the first data row of one against the first of the other. This is correct when the two files are the same list in the same order, with only values edited in place.
By a key column matches rows on a value that identifies the record, like an ID, email or SKU. A row keeps its identity even if it moved, so reordered or inserted rows are reported honestly: moved rows show as unchanged, genuinely new ones as added. Use this whenever rows might have shifted.
What the result tells you
Once matched, each row gets a status:
- Added rows are in the second file but not the first.
- Removed rows are in the first file but not the second.
- Changed rows exist in both but differ, with the specific cells that changed highlighted.
- Unchanged rows are identical, and you can hide these to focus on what moved.
Cell-level highlighting is what makes a diff useful rather than just a count. Seeing that only the Status column changed from pending to shipped is far more informative than knowing the row “changed.”
How to compare two files
Step 1: Add both files
Drop the original into the left slot and the version to check into the right slot of the tool. CSV and Excel files both work, in any combination.
Step 2: Choose how rows match
Stay on “by position” if the rows are in the same order. If anything was inserted, moved or sorted, pick a key column so records match by identity.
Step 3: Read the differences
Filter to hide unchanged rows if you only want what moved. Changed cells are marked so you can see the exact edits.
Related tasks
If the differences turn out to be duplicate rows rather than real edits, the duplicate-row remover clears those out. And if you are comparing two exports that should have been one file, the merge CSV tool combines them with columns aligned by name.