Compare
Find what changed between two versions of a model — and understand why it matters. ModelXcel Pro compares values, formulas, formatting, structure, named ranges, and data validation with formula-aware differencing and smart alignment, then ranks the changes by financial impact and can attribute a moved output back to the specific edits that caused it.
Three ways to compare
The Compare group is a split button: clicking its face runs Compare Workbooks; the dropdown adds two more entry points and the settings dialog. All three feed the same comparison engine and open the same results window — they differ only in what you point them at.
| Command | What you pick | Best for |
|---|---|---|
| Compare Workbooks | Two workbook files (or two open workbooks). | Diffing two separate files — e.g. a model you received vs. the one you sent. |
| Compare to Previous Version | The active workbook vs. an earlier saved version it discovers (or you browse to). | “What changed since the last cut?” — the version-aware review with Material Change Intelligence. |
| Compare Sheets | Specific sheet pairs across two files — including sheets with different names. | Targeted review, or comparing sheets that were renamed or reorganized. |
What it compares
The engine is formula-aware: it compares both the displayed values and the underlying formulas (in A1 and R1C1 form), and classifies each difference. Across a pair of sheets it detects changes to:
- Values (with absolute and percentage deltas, and a financial-significance flag).
- Formulas — added, removed, or modified, sub-categorized (reference / function / constant / operator / structural) and rated for impact.
- Formatting — font, color, border, number format, alignment, conditional formatting.
- Structure — inserted/deleted rows and columns, and added or removed sheets. (A renamed sheet shows as added + removed in a whole-workbook compare; pair renamed or cross-named sheets explicitly in Compare Sheets.)
- Named ranges, data validation, and legacy cell comments.
To keep inserted or deleted rows from cascading into thousands of false differences, the engine applies smart row/column alignment before diffing. The full mechanics — the change taxonomy, the results grid, highlighting, and exports — live on the Comparison results page.
What it writes to your workbooks
The comparison engine is read-only, but two features do write:
- Highlights — from the results window you can color the changed cells directly in a workbook. These are persistent cell fills (the add-in saves your original colors so you can revert in one click), and unlike the Risk Heatmap they are not stripped before save — revert them before saving if you don’t want them in the file.
- Reports & exports — an in-workbook report (added sheets), an
.xlsxexport, a re-openable.mxcmpresults file, and (for Material Change Intelligence) an.xlsxor.pdfexplanation report. Every one is user-triggered; nothing is written automatically.
One more side effect worth knowing: if a comparison changes a cell inside a signed block, the add-in records a block-broken event in that workbook’s Proof & Trust ledger (no-op if the workbook has no signatures). See Material Change Intelligence.
Compare finds differences and impact signals — not correctness
A clean comparison means “nothing changed that we detected,” not “the model is right.” The impact ratings and Material Change Intelligence are deterministic estimates that point you at what moved — they do not prove a formula is correct. For provenance and verification, use Proof & Trust.
In this section
- Compare Workbooks — diff two files.
- Compare to Previous Version — diff the active workbook against an earlier version.
- Compare Sheets — pair and diff specific sheets, with fuzzy name matching.
- Comparison results — the engine, the results window, highlighting, reports, and exports.
- Material Change Intelligence — attribute a moved output to the changes that drove it.
- Comparison settings — tolerance, scope, alignment, financial analysis, and where they persist.