Compare Two Columns in Excel, CSV, or Any List

Copy the first column from Excel and paste it into Column A, then copy the second column into Column B. The tool matches rows by a key column and instantly shows what matched, what's unique to each side, and - if you set a value column - what changed. No VLOOKUP, COUNTIF, or MATCH formulas needed.

Example - two customer exports:

Table A (Jan)	Table B (Feb)	Result
C001	C001	✓ Matched
C002	-	Only in A
-	C003	Only in B

Tip: if your data has a header row, tick First row is a header in Column Setup so column names appear in the dropdowns.

After pasting your data, the Only in A panel shows every key that exists in Column A but has no matching key in Column B. The Only in B panel shows the reverse.

Example - finding discontinued and new products:

Table A (old)	Table B (new)	Result
P001 Laptop	P001 Laptop	✓ Matched
P003 Keyboard	-	Only in A (discontinued)
-	P005 Webcam	Only in B (new product)

Compare Two Lists treats each input as a flat list and does set operations. This tool understands tabular data and matches rows by a key column it can also track value changes.

	Compare Two Lists	Column Compare
Input	One item per line	CSV / TSV / spreadsheet
Matching	Whole-line equality	Match on a key column
Change detection	No	Yes (Track changes in)
Best for	Simple item lists	Database exports, spreadsheets

Rule of thumb: single column → Compare Two Lists. Multiple columns → this tool.

The key column identifies and matches rows between datasets - like the lookup column in a VLOOKUP formula.

Example - matching customers by ID:

Table A	Table B	Result
C001, Alice	C001, Pro plan	✓ Matched on C001
C002, Bob	-	Only in A
-	C003, Basic plan	Only in B

Choose a column with unique, stable identifiers (an ID, email, or order number) - not names or descriptions that might change.

Set a Track changes in column for both sides in Column Setup. Rows where the key matches but the value differs appear in the Changed section, showing the old value (from A) and new value (from B) side by side.

Example - price changes in a product catalog:

Product ID	Table A price	Table B price	Result
P001	99	,099	△ Changed
P002	5	5	✓ Matched

Useful for: spotting price changes between exports, finding updated customer records, comparing config snapshots.

Yes. You choose the key column independently for each side, so columns don't need to be in the same position or share the same header name.

Example - ID column in a different position:

Table A	Table B
Name, ID, Dept	ID, Name, Dept
Alice, E001, Eng	E001, Alice, Eng

Set Match on to A. Column 2 (ID) = B. Column 1 (ID) - the tool handles the mismatch automatically.

The tool matches each row in Table A against the first row in Table B with the same key (VLOOKUP-style).

Example - duplicate key in Table B:

Table A	Table B	Result
C001, Alice	C001, Pro ← first match	✓ Matched
	C001, Basic ← duplicate	Only in B

If Table A has duplicate keys, each row is processed independently against B's first match.

No. All processing runs entirely in your browser using JavaScript. Your data never leaves your device and is never stored anywhere.

The tool runs entirely in your browser with no server-side file size limit. It handles datasets up to around 50,000 rows without noticeable lag on most devices.

For very large files (100,000+ rows), results may take a second or two to appear. To improve performance, paste only the key and value columns you need rather than the full table - fewer columns means faster parsing.

You can paste directly from Excel, Google Sheets, or Numbers - select the cells and paste normally. You can also upload files via the toolbar button in each panel.

Format	Extension	Delimiter
CSV	.csv	Comma
TSV	.tsv	Tab
Plain text	.txt	Any
Excel paste	-	Tab (auto-detected)

The delimiter is auto-detected by default. If the wrong delimiter is detected, select it manually in Column Setup.