Find missing items between two lists.

Decide which list is the reference

When comparing an original export with a newer one, put the original in List A and the newer export in List B. That makes Only in A the missing items and Only in B the additions. Reversing the lists reverses that interpretation.

Copy one column of identifiers from each spreadsheet, excluding the header. Use stable codes when available: a display name may have changed even when the underlying record is the same. This tool compares individual values, not complete spreadsheet rows.

List A — original
SKU-001
SKU-002
SKU-003

List B — newer
SKU-002
SKU-003
SKU-004

Choose how values should match

Open Compare two lists and paste the codes into their respective boxes. Trim whitespace ignores spaces at the beginning and end of a value. Ignore letter case makes values such as SKU-001 and sku-001 match.

Choose those options according to the source system. If letter case or surrounding spaces distinguish real identifiers, keep them significant. Spaces inside a value and punctuation remain significant: SKU-001 and SKU001 are different values.

Read each result in the right direction

For the sample exports, SKU-001 disappeared and SKU-004 was added. SKU-002 and SKU-003 occur in both. All unique values gives the combined set; it is useful when assembling a master list, but does not identify what was missing.

Only in A: SKU-001
In both lists: SKU-002, SKU-003
Only in B: SKU-004
All unique values: SKU-001, SKU-002, SKU-003, SKU-004

Membership is different from quantity

The comparison uses unique values. If List A contains SKU-002 three times and List B contains it once, SKU-002 is still in both lists. That does not mean the quantities agree. Use a spreadsheet pivot table or a grouped database query when duplicate counts matter.

Likewise, moving an item to another line does not count as a change. This workflow answers whether a value is present, rather than whether two ordered documents are identical.

Investigate the missing items

Copy Only in A and check those identifiers in the source system. A missing value could reflect a filter, a renamed identifier, a failed import or a deleted record; the comparison cannot decide which explanation applies.

To prepare those codes for a database lookup, use the SQL list builder and follow the spreadsheet-to-SQL guide. To remove repeated lines from a single export, use Text cleanup. Your pasted lists are processed in your browser.