Guide
Compare Excel Files Online
Two versions of the same report, two exports a week apart — and you need to know exactly what changed. Here are three reliable ways to compare Excel files, from a quick visual check to a repeatable, formula-driven diff.
1. Quick visual check: View Side by Side
For small sheets, open both files and use View → View Side by Side with synchronous scrolling. It costs nothing to set up, but it depends on your eyes — fine for a dozen rows, risky for a thousand.
2. Cell-level diff with a formula
If both files share the same layout, add a comparison sheet and fill it with
=IF(A1<>[Book2]Sheet1!A1,"DIFF",""). Every mismatched cell lights up, and
you can filter or count the DIFF flags. This is the fastest way to answer “did anything
change?” across a whole grid.
3. Row matching across files with VLOOKUP or COUNTIF
When rows can move around, compare on a key column (an ID, an email, an
order number) instead of by position. =COUNTIF(other!A:A,A2)=0 marks rows that
exist in one file but not the other; VLOOKUP or XLOOKUP pulls the
matching value over so you can compare amounts, dates, or statuses side by side.
Doing this in the browser
The same key-column approach works in TableDI, an
online data table: load both sheets and use the formula panel — including
VLOOKUP and COUNTIF — to match rows and flag differences without
leaving the browser. The TableDI docs cover each
formula the panel supports.
Which method should you use?
- Same layout, quick answer — the cell-level IF formula.
- Rows move around — match on a key column with VLOOKUP or COUNTIF.
- No desktop Excel at hand — an online table with a formula panel.
FAQ
How do I compare two Excel files for differences?
Open both workbooks and use View → View Side by Side for a quick visual check. For a cell-level report, add a formula like =IF(A1<>Sheet2!A1,"DIFF","") in a copy of the sheet, or match rows across files with VLOOKUP or XLOOKUP on a shared key column.
Can I compare Excel files without installing anything?
Yes. Formula-based comparison works in Excel itself with no add-ins. If you prefer a browser, an online data table like TableDI lets you load both sheets and match rows with VLOOKUP or COUNTIF from its formula panel.
How do I find rows that exist in one file but not the other?
Use COUNTIF against the other file’s key column: =COUNTIF(other!A:A,A2)=0 marks rows missing from the other file. Filter on that column to list them.