Guides
How to Compare Two Excel Files and Find the Differences
Updated 2026-10-18
The quote went back and forth a few times and a colleague says they "only changed a few numbers". Finance sends a new budget and you want to know exactly what moved. Reading row by row works for twenty rows; for five hundred you will miss something.
Method 1: View Side by Side
Open both files, then View → View Side by Side and turn on Synchronous Scrolling. Both windows scroll together. Good for short sheets when you roughly know where to look; once rows were inserted and the two versions drift apart, it stops helping.
Method 2: a formula with conditional formatting
Put both versions in one workbook (say sheets Old and New), then on New:
- Select the data range, Home → Conditional Formatting → New Rule → Use a formula to determine which cells to format.
- Enter
=A1<>Old!A1 (A1 being the top-left cell of the selection, no $ signs) and pick a fill color.
Different cells light up. The catch: it compares the same positions only, so one row inserted near the top marks every row below it as different, and a changed formula with the same result goes unnoticed.
Method 3: Spreadsheet Compare
Some Office editions (such as Office Professional Plus and Microsoft 365 Apps for enterprise) include Spreadsheet Compare, which lists differences in values, formulas and formatting. Home and Student editions usually don't have it, and it doesn't exist on Mac.
Method 4: an online cell-by-cell diff
Upload the old and new versions to xlszip's compare tool, nothing to install:
- sheets are paired by name; a sheet on one side only is reported as added or removed;
- rows are aligned by their whole content first, then by the first column (IDs, names), so inserted and deleted rows are listed on their own instead of turning every row below into a change;
- displayed values and formulas are compared, not formatting; dates show as dates, not serial numbers;
=B2*2 becoming =B3*2 because a row was inserted is not a change;
- the page shows the count per sheet and the first 60 differences; the downloaded difference list workbook has all of them;
- tick Also export a marked-up copy and the zip also holds the new version with changed cells filled yellow and their old value and formula in a comment, and added rows filled green, so you can review in context.
Sheets over 50,000 rows are matched by row number (everything after an inserted row counts as changed), and the page says so.
Tips
- Make sure sheet names match; a renamed sheet shows up as one removed and one added.
- If only some columns matter, trim both versions to those columns first.
- Keep a copy of the original before sending a file out for edits, so you can compare when it comes back.