Compare CSV files by record:not line number

Choose the column or columns that identify a record. Reordered rows stay the same; additions, removals, field changes, duplicate keys and null keys become explicit.

Get early access See the keyed diff

Private early access · macOS & Windows

Product previewKeyed record comparison

CSVProof

Local file

vendor-september.csv×

DataTransformCompareIssues 6RecipeRun report

12,201Unchanged

184Added

93Removed

41Changed

3Duplicate keys

Statuscustomer_idnamecountry beforecountry after

Changed001284Nord ASNOSE

Added001309Atlas GoodsDK

Duplicate001177Meridian SupplyNONO

Removed001101Old HarbourGB

Line 418 is not a customer

A line diff treats row order as meaning. CSVProof first matches records using a key such as customer_id, then shows the field-level changes that matter.

August · line 18001284,Nord AS,NO

September · line 418001284,Nord AS,SE

Matched by customer_idcountryNO→SE

Five answers, not a wall of red and green

Added

A key appears only in the new file.

−

Removed

A key appears only in the earlier file.

Changed

The same key has one or more field changes.

×2

Duplicate

A key cannot identify one record uniquely.

Unmatched

A null or invalid key needs a decision.

Runs locally in your browser

Free keyed compare

The local two-file compare will live here as the next focused tool.

No file upload. No CSV content in analytics. The tool itself is reserved for the dedicated implementation round.

Get compare access

Save what “same record” means

A one-off CSV diff answers “what differs today?” CSVProof desktop saves the key, parser settings, comparison rules and exception decisions as a versioned comparison contract.

Composite keys such as account + location
Ignored fields such as export timestamps
Explicit numeric, date and text tolerances
Per-field changes with before and after values
Duplicate, null and ambiguous-key review
Parser settings for both files
Reusable contract and downloadable evidence

Product previewReview table exceptions

CSVProof

Local file

vendor-september.csv×

DataTransformCompareIssues 6RecipeRun report

Duplicate customer_idChoose the row to keep

Keeprowcustomer_idname

●177001177Meridian Supply

○902001177Meridian Supply AS

Make the next comparison a rerun, not a rebuild

CSVProof is currently in private early access for macOS and Windows.

Get early access