Check your Excel corpus first.

Drop a workbook. SumOffice tells you what works, what doesn't, and what it depends on — then opens it, runs it, saves it back, and Excel opens the result. Four steps, all measured, before you switch anything.

Drop the workbook — here, or send it to the Check bot in Slack or Telegram; nothing in it is run; deleted after 24 hours.
Read the report — every macro with its route, every function known or unknown, every data source, as “N of M”.
Open it and run — the “Open it” button: the same workbook in SumSheet on our server, formulas recalculating, nothing installed.
Save, open in Excel — the file comes back with its VBA byte for byte; inside your own Nextcloud in three steps.

Excel says the file is corrupted? The same door reads damaged packages too: which rows are broken, and a repaired copy with every intact row.

What you get, in seconds

Verdict	One of the four words our Compatibility Center uses about a workbook's macros: NativeSumSheet can attempt to run them in its own sandbox Migrationwaits for work on our queue Excel bridgestays in Excel by design Preserve onlysource we could not classify — kept byte for byte Workbooks without executable logic are called what they are: a table.
Formulas	How many, how many distinct functions, and how many of them the engine knows by name — with the unknown ones listed. Nested forms are checked by opening the workbook; the “Open it” button is that test.
Data logic	PivotTables, Power Query, external links, connections, charts, tables.
Macros	How many macros Excel would offer you, how many of them route native, every entry point with its route, what blocks the rest (events, external automation, COM components, UserForms, libraries).
Open it	The same workbook opened in SumOffice, in your browser, on our server — the real engine, the real file.

Every number says what it counts

Percentages are written as “N of M”, never alone. A route describes what we cover today, not a promise that a macro behaves as in Microsoft Excel; only a recorded run against Excel says that. Missing evidence is not proof of absence: a file we could not read is reported as unreadable, not as “no macros”.

Calibration, so you know what these words mean on real files: on the public Enron corpus — 3 738 macro workbooks, 13 870 macros a person can start — 73 % of the macros route native, 18 % wait for work on our queue, 8 % stay in Excel by design. Read, not run.

What happens to your file

It is stored on one server, read three times (package structure, formula names, VBA source), and deleted after 24 hours or sooner.
Nothing in it is executed — no macro, no query, no external connection.
It is not copied to storage, analytics or third parties. If you leave an address, we write to you about this file and nothing else.
Your original is never modified. Open the same workbook in the SumSheet app, run your macros and queries, save — and open the result back in Excel. Check it yourself: nothing about your setup has to change first.

Leaving Microsoft? The report tells you what your corpus depends on. The same workbook keeps working inside your own Nextcloud — three steps, measured. What it cannot do for you — port the macros and Power Query sources that route “migration”, or audit the whole corpus before the move — is a change under your process: from 600 € per macro or source, the audit by estimate, price and date before we start. Order it →

Regular work with your workbooks — editing, saving back, macros running — is the SumSheet app (Windows, macOS, Linux, Android, iOS) and the SumSheet view-SDK for your own products; see Capabilities and Developers.