ASSEMBLY FILE PREPARATION
BOM version comparison
Compare two revisions by reference designator. See added, removed and changed parts without confusing regrouped rows with design changes.
Previous BOM
XLSX / UTF-8 CSV, TSV, TXT · up to 5 MB and 10,000 rows
No file loaded
New BOM
XLSX / UTF-8 CSV, TSV, TXT · up to 5 MB and 10,000 rows
No file loaded
Quantities are per board and must match the listed references. Comparison expands reference groups and tracks MPN, manufacturer, value, footprint, DNP and mounting type. Renamed references appear as removed and added. Case differences in part fields are reported.
Import both versions to begin. Files stay in this browser.
Revision changes
The CSV contains all added, removed and changed references; search filters do not limit the export. Source files remain unchanged.
Before you send the files
Which formats and fields are supported?
Use UTF-8 CSV, TSV or delimited TXT with a header. KiCad whitespace .pos files with the standard Ref / Val / Package / PosX / PosY / Rot / Side header are also supported. Excel .xlsx files are supported. Choose a worksheet after import; its first used row must be the header. Use values-only sheets: formulas and Excel error cells are rejected. Older .xls files must be saved as .xlsx or CSV. Map unfamiliar headers after import. Comma, semicolon, tab and pipe delimiters are supported.
BOM quantities are per board. References can be grouped as R1, R2 or R1-R5. Manufacturer part numbers are required for fitted items. DNP accepts yes/no, true/false, 1/0, DNP and DNF; blank means fitted. Mounting type accepts SMT, THT and Other. A placement file needs one reference, X, Y, rotation in degrees and side per row.
What does the reference comparison check?
With both valid files loaded, we identify placements absent from the BOM, placements marked DNP, fitted BOM references without placement data, and different package names. Missing placements are review items because some parts are hand-assembled. BOM rows marked THT or Other are excluded from the missing-placement check. Comparison waits until file errors are resolved.
What does a clean result mean?
It means the supplied data passed these format and consistency checks. We do not verify component availability, pin 1, polarity, footprints, physical placement, solderability, electrical function or manufacturing readiness. Package-name differences can be legitimate library naming differences. Confirm origin, bottom-side convention and rotation with your assembler.
Where are my files stored?
These tools process files in browser memory and do not upload them or save them in browser storage. Clear the files or reload to discard the current session. Downloads are saved by your browser. The site’s account and search controls are separate from file processing.
Open-source software
CSV parsing uses PapaParse 5.7.0, distributed under the MIT license. Read the bundled license. Excel parsing uses SheetJS Community Edition 0.20.3 (Apache-2.0). SheetJS license. File checks and this interface are implemented for PCBA Partner.