Compare two CSV files by the column that identifies each row.
A line-by-line diff treats a new sort order as a change. MatchDock pairs rows by the record ID you select, then separates changed values from records found in only one file. Duplicate and empty keys stay visible as exceptions.
CSV contents are parsed and reconciled locally in your browser.
Source A
source-a.csv
| Record ID | Customer | Amount |
|---|---|---|
| INV-101 | Northstar | 125.00 |
| INV-102 | Harbor | 80.00 |
| INV-103 | Willow | 42.00 |
Source B
source-b.csv
| Record ID | Customer | Amount |
|---|---|---|
| INV-103 | Willow | 42.00 |
| INV-101 | Northstar | 125.01 |
| INV-104 | Atlas | 90.00 |
Rule: Key: Record ID · Compare Customer and Amount · Amount tolerance: 0.02
- INV-101
- Within tolerance
- INV-102
- Only A
- INV-103
- Matched
- INV-104
- Only B
Compare records, not line numbers.
Choose a unique field such as transaction ID, invoice ID, email, or SKU. If one field is not unique, combine fields into a composite key. Map column names when the exports use different labels. Row order never acts as a hidden matching rule.
When keys need attention
- Repeated ID
- Reported as duplicate or ambiguous; no first-row guess.
- Missing ID
- Reported as an invalid key.
- Small value difference
- Within tolerance only when you explicitly set a numeric rule.
Try the example in MatchDock.
Download these fictional files, start a reconciliation, and upload them as Source A and Source B. Select Record ID as the key, compare Customer and Amount, then set Amount to numeric with an absolute tolerance of 0.02. Review the results before exporting an XLSX workbook.
Need a broader view of added and removed rows? See the two-direction missing-row check.
Questions about CSV comparison
- Do the rows have to be in the same order?
- No. MatchDock matches by your selected key, even when exports are sorted differently.
- Which CSV delimiters are supported?
- Comma, semicolon, and tab. If detection is uncertain, select the delimiter explicitly when preparing the source.
- What encoding should I use?
- Use UTF-8 CSV; a UTF-8 byte-order mark is accepted. Check the preview before mapping columns.
- Can I repeat the same comparison?
- With Pro, you can save the configuration as a workflow, then select fresh local files for the next run. Spreadsheet contents are not saved in the workflow.
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.