Bill of materials, redlined
Upload two BOM revisions and get a redlined diff in seconds — added, removed, and changed lines flagged automatically. Flat or multi-level. Nothing leaves your browser.
| Status | Part | Description | Qty |
|---|---|---|---|
| Changed | HSG-201 | Housing Body | 1 |
| Added | SHF-303 | Shaft Retaining Clip | 2 |
| Removed | GTR-603 | Idler Gear 18T | 1 |
Product
Indented or parent-child structures. Matches parts by their full assembly path, not just part number.
Additions, removals, and changes read like a marked-up engineering document — not raw rows to eyeball.
Files are parsed client-side. Nothing is uploaded to a server — useful when the BOM is client-confidential.
Download the full diff as CSV — status, level, path, and before/after values — ready to drop into an ECO.
How it works
Drop in a CSV or Excel export for the baseline and the comparison BOM.
Structure and columns are auto-detected — part number, description, qty, revision, level.
Filter by change type, search a part, export the full diff.
FAQ
CSV and Excel files (.xlsx, .xls). Column names don't need to match any fixed template — the tool auto-detects part number, description, quantity, revision, reference designator, and cost columns, and you can adjust the mapping if it guesses wrong.
No. Both files are parsed and compared entirely in your browser. Nothing is uploaded anywhere — useful when the BOM itself is client-confidential.
By part number combined with its full position in the assembly, not just the bare part number. That means the same part number reused under two different sub-assemblies is tracked separately, rather than being confused with itself.
Yes — flat single-level lists, indented BOMs with a Level column, and parent-child BOMs with an explicit Parent Part Number column are all supported.
Yes. If your two files come from different systems or exports with different column names or order, you can map each file's columns independently instead of using one shared mapping.
Yes — the full diff exports as a CSV, including status, level, assembly path, before/after values, and line cost impact if you mapped a cost column.
Yes, a free account is required to use the comparison tool and to save comparisons for later. Your BOM files themselves are still never uploaded — the account just gates access to the tool and stores your saved comparison history.