Compare Excel Files

Compare two Excel files and see exactly what changed

Opening two versions of a spreadsheet side by side and hunting for the differences is slow and easy to get wrong. This tool reads both files, matches the rows up, and hands back a single Excel workbook that spells out every change: which cells differ, what they used to say, what they say now, and which rows were added or removed entirely.

Rows are matched on a key, not on position

You choose a key column — an ID, an email address, a SKU, anything unique to each record. Rows are paired using that key rather than the order they appear in, so a file that has been re-sorted between versions still compares correctly. A row whose key exists in one file but not the other is reported as added or removed, rather than as a wall of false changes.

How it works

1. Upload both files — the older version as File A, the newer one as File B. Both need to be .xlsx or .xlsm.
2. Pick the sheet in each file. They do not have to share a name or sit in the same position.
3. Choose the key column from the columns the two sheets have in common.
4. Download the comparison as a highlighted .xlsx.

What you get back

One workbook with five sheets:

• Summary — counts of changed cells, added rows and removed rows
• Changes — one line per changed cell: key, column, old value, new value
• Added Rows — full records present in File B but not File A
• Removed Rows — full records present in File A but not File B
• Highlighted (File B) — the new file in full, with changed cells shaded yellow and added rows shaded green, so you can read changes in context

Trivial differences are ignored on purpose

Values are normalised before being compared, so 42000 and 42000.0 do not count as a change, a blank cell and an empty cell are treated as the same thing, and leading or trailing spaces are stripped. The aim is a list of changes that are all worth reading, rather than one padded out with formatting noise

What people use it for

• Checking a price list or rate card against last month's version
• Verifying that a data migration moved every record across intact
• Reviewing what a colleague changed in a shared workbook
• Reconciling a supplier catalogue or stock file between updates.
• Auditing a membership or payroll export period on period

Common questions

Do the two files need identical columns?

No. Columns common to both sheets are compared, and the tool also reports which columns exist in only one of the files — so a renamed or dropped column is obvious rather than silently ignored.

Does it compare formulas or results?

Results. A formula is read as the value it currently produces, which is normally what you want when checking whether the numbers moved.

What if my key column has duplicates?

Keys are expected to be unique to each row. Where the same key appears more than once, matching becomes ambiguous — Detect Anomalies will find repeated values in a column that ought to be unique.

What are the file limits?

.xlsx and .xlsm, up to 10 MB per file, two files per comparison. Three comparisons a month without an account.

What happens to my files?

Both are processed for your session and deleted within the hour. Neither is kept, shared, or used for anything else.