Contact
12 programs
Explore the site

Excel Compatibility and Migration Decisions

Quick answer

Choose the destination by what the recipient must do, not by whether it opens an XLSX file. A workbook that displays yesterday’s figures can still fail its migration if a required macro, refresh operation or calculation no longer works. Preserve the source and accept a separate trial only against written requirements.

Scope: Excel for the web and migration planning for desktop Excel workbooks; official documentation checked 21 October 2026. This is a decision reference, not a Windows, Mac or mobile execution test. Free browser access is not evidence of desktop feature parity; consult versions and availability before choosing an edition.

Identify the destination and the job

Record the recipient’s application, edition, platform and version or service date. Ask whether they need to read a report, change inputs, refresh linked data, run automation or return an editable workbook. Those are separate acceptance requirements.

Microsoft documents differences between browser and desktop Excel, including supported formats and feature behavior. Its comparison also contains older server environments, so match each statement to the actual destination rather than treating every row as a universal cloud rule. Microsoft’s browser comparison

A concrete blocker is VBA: Excel for the web cannot create, run or edit VBA macros, although existing macros can remain in a workbook edited there. Preservation is not execution. If the recipient’s process depends on a VBA button, do not approve a browser-only replacement just because ordinary cells still calculate. Microsoft’s VBA guidance

Make an acceptance inventory

For each dependency, record its location, required behavior, test, expected result and fallback:

  • Calculations: critical formulas, named ranges, array outputs, date conventions and required error handling. Test changed inputs, not just cached totals.
  • Automation: VBA, scripts, add-ins and any files or services they access. List each separately; a replacement implementation needs its own review.
  • Data: connections, refresh credentials and source availability. Decide whether a dated snapshot is acceptable or live refresh is essential.
  • Interaction: controls, validation, protection and the cells users must edit. Check an authorized recipient’s actual workflow, not only the owner’s view.
  • Presentation: charts, print areas and required report pages. A visually similar sheet is not proof of equivalent calculations.
  • Collaboration: authoritative file location, owner, intended viewers/editors and how returned changes will be reconciled. Do not infer these from the exported file’s extension.

Use four statuses: documented constraint, observed pass, observed failure and untested. Documentation alone cannot establish an observed pass.

Select a bounded trial

Keep the untouched source in its original format, including its automation where applicable. Give the trial a different name and record its source date. Use synthetic data first; do not activate unfamiliar macros or external connections to make a test succeed.

The existing file-format exercise tests the difference between a recalculating workbook and a CSV value snapshot. It uses Microsoft 365 Excel for Windows desktop, not the free browser interface. Use its expectations only in that stated scope; if that application is unavailable, leave its execution untested.

For example, a proposed acceptance record for a weekly report could require three independent outcomes: edited quantities update totals, the required refresh obtains this week’s data, and the recipient can produce the agreed report pages. Passing the arithmetic check alone leaves the other two unresolved. No application run is claimed for this example.

Decide whether to move

Accept the trial only when every essential requirement passes in the receiving environment. A report-only copy can be acceptable when the recipient explicitly needs a fixed snapshot, but label its date and limitations rather than presenting it as a working replacement.

Keep the original workflow if a necessary macro or refresh remains blocked. If results change, return to a fresh source copy rather than repeatedly converting the damaged trial. Use Excel troubleshooting to separate calculation problems from file identity and environment problems. Do not retire the source until the recipient has checked the actual deliverable.