How do I find what changed between two BOM revisions?

Last checked 2026-11-11 against the live tool page.

Short answer

The BOM comparison tool lines up two revisions by reference designator. It shows added, removed and changed parts. Regrouped rows are expanded, so they do not look like design changes.

Steps

Import the previous BOM and the new BOM (Excel, CSV, TSV or TXT; up to 5 MB or 10,000 rows).
Quantities are per board and must match the listed references.
Review the differences. The tool tracks MPN, manufacturer, value, footprint, DNP and mounting type.

Things to know

A renamed reference appears as removed and added.
Case differences in part fields are reported.
Data issues such as a missing MPN are listed but do not block the comparison.
Files stay in your browser.

What a clean result does not mean

It shows the two files differ or match in the fields listed above. It does not check stock, pricing or whether the new part fits the footprint.

BOM checker to check the new BOM before ordering.