Known Differences

This page tracks meaningful differences versus openpyxl/Excel behavior.

Current guidance

• WolfXL focuses on high-value openpyxl-style workflows, not complete API parity.
• Feature support should be validated via the compatibility matrix and fixture tests.

Modify mode notes

• Modify mode uses a surgical patcher for targeted changes.
• Preserve-value behavior for style-only edits is regression-tested.

App-level evidence limits

• PowerView-bearing workbooks are treated as app-unsupported evidence in the local Microsoft Excel smoke harness. Excel can block those files behind a read-only unsupported-content prompt, so they are useful for package-fidelity radar coverage but not for proving clean editable Excel open/close behavior. A Microsoft Error Reporting SIG_FORCE_QUIT / merp log after this kind of blocked prompt is not, by itself, treated as an OOXML repair/corruption signal; the repair signal remains an explicit Excel repair/error dialog.
• The interactive Excel evidence gate is intentionally stricter than package preservation. On 2026-05-08, targeted source-workbook probes passed for: pivot state, slicer state, timeline state, external-link state, macro project presence, and embedded-control state. The combined strict audit over all six source-workbook probe reports now reports ready=true with no incomplete reports: /tmp/wolfxl-interactive-evidence-external-oracle-all-20260508.json.

Contributing a difference report

When reporting a difference, include:

1. Minimal workbook sample
2. Expected behavior (Excel/openpyxl)
3. Actual WolfXL behavior
4. Repro code snippet

Link issue reports to benchmark/fidelity artifacts when possible.