In Excel: use =A2=B2 for row-by-row matches, or =COUNTIF($B:$B,A2)>0 to check whether each value in column A appears anywhere in column B.
On this page7
Only in A: 2 · Only in B: 1
What this does
Comparing columns has two different meanings. Row-by-row comparison asks whether A2 equals B2, A3 equals B3, and so on. List comparison asks whether each value from one column exists anywhere in the other column. The first uses a direct equality test; the second uses COUNTIF, MATCH or XLOOKUP. Keep the inputs visible and clearly labelled and the whole thing stays auditable — anyone who opens the file later, including you, can see at a glance exactly what feeds the result and change one assumption without hunting through the formula. Treat “compare columns excel differences” as a small repeatable workflow rather than a one-off click you hope to remember next time. Use a small test block before the live file, so any surprise in the affected columns shows up while it is still harmless. When a formula is involved, keep the inputs labelled beside it, reference cells instead of typing values, and apply number formatting only after the result checks out. That turns a layout choice that keeps the sheet readable and sortable into a method you can reuse, explain, and defend when the workbook leaves your screen.
A worked example
Column A has invoice IDs from system 1 and column B has IDs from system 2. In C2, =A2=B2 returns TRUE only when the two rows match exactly. If the rows are not aligned, use =COUNTIF($B:$B,A2)>0 in C2; invoice 1042 returns TRUE if it appears anywhere in B, even on a different row. Column comparison is core spreadsheet reconciliation: invoices, IDs, email lists, product codes, migration checks and any workflow where two systems should agree. One habit worth forming early: name the cells that hold your inputs, so the formula reads in plain language instead of a string of cell addresses. A reviewer — or you in three months — can then follow the logic without decoding what B7 and D2 were supposed to mean, which is most of what makes a sheet maintainable.
In Google Sheets
Google Sheets handles this almost identically to Excel. The formula syntax above is the same, and the menu lives under a slightly different label rather than a ribbon tab. Use the platform toggle at the top of the page to switch every keyboard shortcut between Windows and Mac, and expect at most cosmetic differences in naming. Keep this page bookmarked for the next time the same question comes up. Better still, rebuild the example once in your own sheet — doing it yourself, with the tool above to check against, is what turns a copied formula into a technique you own. Treat “compare columns excel differences” as a small building block rather than a chore. Once the inputs sit in their own cells and the formula reads from them, the same setup answers a dozen related questions with a tweak, and Excel keeps every dependent figure current as the data changes. The tool above is there so you can rehearse and verify before committing anything to a real workbook; the steps and worked example are there so the logic sticks. Get it right once and it stops costing you time — it starts saving it, every time the question comes back around.
Common mistakes
- Using
=A2=B2when the two lists are sorted differently. - Forgetting absolute references in $B:$B, so the lookup range shifts while copying.
- Treating numbers stored as text as equal to real numbers without cleaning the data.
- Ignoring leading/trailing spaces;
TRIMboth columns when matches look visually identical but fail.
Frequently asked questions
How do I compare two columns row by row?
Use =A2=B2 and fill down. TRUE means the values in that row match exactly.
How do I find values in A that are missing from B?
Use =COUNTIF($B:$B,A2)=0 and filter TRUE results.
Can conditional formatting compare columns?
Yes. Use a formula rule such as =$A2<>$B2 for row differences, or COUNTIF for list membership.