MSTENGINEERING INTELLIGENCE
FREE TOOLS

BOM Compare

See what changed between two bills of materials.

Runs on your device
No sign-in. No file upload.

Match revisions by part number. See what changed before updating an assembly.

See the worked example ↓

01 Before

02 After

Part numbers are case-sensitive. Duplicate part numbers must be resolved first.
SYNTHETIC WORKED EXAMPLE

What changed in this bracket assembly’s parts list?

Two flat BOM revisions, four rows each. These are the expected findings from the sample, not results from your files.

Revision A → Revision B · expected comparison
Part numberRevision ARevision BFinding
BRK-1001 · Aluminium 60611 · Aluminium 6061Unchanged
PIN-0202 · Steel2 · Stainless steelMaterial changed
SCR-M64 · Steel6 · SteelQuantity +2
WSH-M64 · SteelNot presentRemoved
NUT-M6Not present6 · SteelAdded
  1. Load both revisions. Choose Try sample revisions above, or download the two CSVs and open them with Choose CSV.
  2. Check the column mapping. Confirm part number, quantity, description and material. Select Compare BOMs.
  3. Review and export. Expect 1 added, 1 removed, 2 changed and 1 unchanged part. Export the full comparison as CSV.
Download revision A CSV ↓Download revision B CSV ↓

Check a revision before replacing parts

Export each BOM as CSV UTF-8 from your spreadsheet or CAD/PDM system. Map the part number and quantity columns, then compare. Description and material changes appear when those columns are included.

Rows match by the exact, trimmed part number. A changed part number appears as a removal and an addition. Item order is ignored. Quantities must use decimal numbers with a dot, without units or thousands separators; this tool does not convert units or reconcile assembly hierarchies.

BOM still in a drawing? Extract the table first →Review repeated parts and missing quantities →Preparing P&ID, BOM and model data for an assembly workflow →