Find the rows that exist in only one of two Excel files.
Check both directions in one run: records in the first export but absent from the second, and records that appeared only in the second. MatchDock uses the record key you choose, rather than row position or a single-column visual diff.
Both XLSX and CSV files are processed locally in your browser.
Source A · earlier export
customers-august.xlsx
| Customer ID | Name |
|---|---|
| C-101 | Northstar |
| C-102 | Harbor |
| C-103 | Willow |
Source B · later export
customers-september.xlsx
| Customer ID | Name |
|---|---|
| C-103 | Willow |
| C-101 | Northstar |
| C-104 | Atlas |
Rule: Key: Customer ID · Compare: Name
- C-101 / C-103
- Matched
- C-102
- Only A · removed or missing
- C-104
- Only B · added or unexpected
Why check both directions?
A lookup from the old file into the new one finds records that disappeared. It does not tell you which records appeared unexpectedly in the new file. MatchDock reports Only A and Only B separately so you can investigate both questions without reversing the formula or swapping files.
Only A — present in the earlier export, absent from the later one.
Only B — present in the later export, absent from the earlier one.
Use a key that identifies the whole record.
1. Choose two exports
Load the earlier file as Source A and the later file as Source B. Confirm each worksheet and header row.
2. Map the identity
Use a stable ID, or a composite key if one column is not unique. Do not put changed values into the key just to force a match.
3. Review each exception
Filter Only A and Only B; inspect duplicates and invalid keys before calling a row missing.
A repeated key is not a missing row.
A first-match lookup can hide a second row with the same ID. MatchDock reports duplicate or ambiguous key groups explicitly instead of pairing the first occurrence and treating the rest as missing. Empty or unusable keys are reported separately too.
If the report has one row per customer and month, use Customer ID + Month as the key. Matching by Customer ID alone would make that export ambiguous.
Your spreadsheet contents stay in your browser.
MatchDock parses and reconciles your files locally. Spreadsheet contents are not uploaded to MatchDock servers, and Excel exports are generated in your browser.
Ready to review the exceptions?
Start with two Excel or CSV exports. Choose the records that should match, apply explicit rules, and keep uncertain outcomes visible.