LIST COMPARE · GUIDE & EXAMPLES

A practical guide to comparing lists

Work through names, product codes, repeated rows and source positions. Each example uses fictional data you can compare locally.

Open List Compare

THE SHORT VERSION

Paste. Compare. Carry on.

Paste your lists

Names, emails, product codes, or anything else. Put one item on each line, or paste a column from a spreadsheet.

Choose what counts as a match

Ignore capitalization or trim surrounding spaces. Blank lines are skipped, and duplicate items are counted once.

Take the results with you

Copy individual lists, or take a change brief showing additions, removals and shared-item count differences from A to B. Items keep their original order; shared items use List A’s spelling.

IDENTIFIERS ARE TEXT, NOT QUANTITIES

Compare product codes as text.

A code such as 00042 can identify a different product from 42. Compare the characters you actually have, rather than converting both to a number. This fictional example also includes two long codes that differ only in their final digit.

Prepare one identifier column

Copy only the code column, without its heading, and paste one item per line into each list. Keep the original source available. Before entering or importing codes into Excel, preserve them as text; Microsoft explains leading zeros, long numbers and text imports. Check the pasted characters, because worksheet formatting and previously converted values can hide a problem.

List A · original codes

00042
042
12345678901234567
Part-A
Part-A

List B · codes to check

42
042
12345678901234568
 part-a

For this example, leave Ignore capitalization and Trim spaces enabled. The last B item has a space at each end. List Compare keeps codes as text: trimming does not remove zeros, and long digit strings are not rounded into numbers.

Expected results with the two defaults

Only in A · 2: 00042
12345678901234567
In both · 2: 042
Part-A
Only in B · 2: 42
12345678901234568

00042 and 42 stay separate. The shared 042 is a third distinct code; no zero-padding rule is guessed.
The two 17-digit codes stay separate because the final digit differs. If a spreadsheet already rounded a code, this tool cannot recover the original digits.
Part-A matches part-a only after applying the selected case and space rules. Shared output uses A’s spelling. If capitalization is meaningful in your codes, turn Ignore capitalization off and compare again; if surrounding spaces are meaningful, turn Trim spaces off.
A has 5 rows but 4 unique codes: its repeated Part-A counts once in the membership results. The occurrence-count view separately shows 2 in A versus 1 in B. Repeated rows are not proof of a stock quantity.

An unmatched code means its text is absent under your chosen rules, not proof that a product was discontinued. Changing a damaged cell to Text afterward cannot reconstruct lost zeros or rounded digits. Return to the original source rather than adding zeros or editing codes until the counts look right. This compares one text column; it does not join product records, validate identifiers or compare prices.

Compare your code columns

A WORKED EXAMPLE

Did the roster change—or just the formatting?

Compare two name lists copied from a spreadsheet. Paste only the full-name column, without its heading. In this fictional example, List A is the previous roster and List B is the current roster.

List A · previous roster

Mina Patel
Oscar Lee
Nora Shah
Nora Shah
Eli Grant

List B · current roster

 mina patel 
OSCAR LEE
Nora Shah
Theo Park

Leave the two defaults enabled: Ignore capitalization and Trim spaces. In B, Mina’s name is lowercase with a space at each end. Oscar’s name is uppercase.

Expected changes from A to B

1 added: Theo Park
1 removed: Eli Grant
3 retained: Mina Patel, Oscar Lee, and Nora Shah

1 duplicate collapsed: Nora Shah appears twice in A but counts as one unique name in the comparison.
2 matches explained: Mina Patel matches “ mina patel ” after trimming spaces and ignoring capitalization. Oscar Lee matches OSCAR LEE when capitalization is ignored.

Open Why these results? after comparing to inspect those matches and the repeated row. Shared names keep List A’s spelling. Copy brief gives you the counts and the full added and removed names, with A as before and B as after.

“Removed” means absent from the supplied current list, not proof that someone left. This is exact text matching after cleanup, not fuzzy identity resolution: nicknames and different spellings are not merged. If two people may share a name, compare stable identifiers such as employee IDs instead.

Compare your own lists

WHEN REPEATED ROWS MATTER

Same items. Different number of rows.

Two lists can have exactly the same unique items but different numbers of repeated lines. Here is a fictional Bolt-and-Nut example. Each line is one occurrence; there is no separate quantity column.

List A

Bolt
Bolt
Nut

List B

Bolt
Nut
Nut

The ordinary comparison finds 0 only in A, 2 in both, and 0 only in B. No membership change is not the same as no count change.

Expected shared-item occurrence differences
Item	In A	In B	B − A
Bolt	2	1	−1
Nut	1	2	+1

After comparing, open Shared items with different counts. Copy brief includes this count check alongside additions and removals. Repetitions are grouped with the same capitalization, space and Unicode rules as the main comparison; changing a rule can change the counts.

This checks supplied text rows, not stock levels, quantities or identities. Two people can share a name, and repeated rows can be intentional. Verify their meaning before changing your source data. Excel users can also count occurrences with COUNTIF or a PivotTable.

Check your own repeated rows

FIND A RESULT BACK IN YOUR INPUT

Result number is not source row.

After comparing, select Show source rows to see where an item first appeared in each pasted list. In this fictional example, the numbers and quotation marks below are explanation labels, not part of the lists. "" marks a blank line.

List A: pasted lines

1. "Bolt"
2. ""
3. "Nut"
4. "Bolt"

List B: pasted lines

1. "Washer"
2. " nut "
3. ""
4. "BOLT"

With the default capitalization and space rules, Bolt and Nut are in both lists; Washer is only in B. These are their first source rows:

First matching line in the original paste
Item	List A row	List B row
Bolt	1	4
Nut	3	2
Washer	Not present	1

Rows start at 1 at the top of each paste, not at a worksheet’s original row number. Blank lines count toward the position, even though they are not compared. Duplicate matches point to their first occurrence under your selected rules; visually wrapped text is still one line. This display does not add row numbers to copied items, downloads or the change brief. In Excel, MATCH can find the first relative position in a selected range; its matching rules differ from this tool’s.

Find rows in your own lists

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