Repair an Excel file that won't open

What to do when Excel won't open your file

A workbook that refuses to open is rarely destroyed. A .xlsx is a zip archive of XML documents, and Excel checks the whole package before it shows you anything: one missing index, one malformed part, and it refuses the file entire — including the several megabytes of perfectly readable rows sitting next to the damage. That is the gap this tool works in.

The faults behind the same error message

• The download stopped early. The commonest one by far. Half a workbook is still half a workbook: the sheets that arrived are intact, and the directory at the end of the file — the part Excel reads first — is what never made it.
• The zip directory is damaged. Every part of the package also carries its own header, so the contents can be found by reading the file directly even when the index that lists them is gone.
• A sheet's XML broke mid-write. What a crash during save leaves behind. The rows on either side of the break are usually fine, and are read one at a time rather than as a document.
• It isn't a .xlsx at all. An HTML table, a CSV or an XML spreadsheet that something saved under a spreadsheet extension. Nothing is damaged here — the data just needs writing into a real workbook.
• It's encrypted, not broken. A password-protected workbook looks like a foreign format from the outside. That one needs the password, not a repair.

What comes back, and what doesn't

The rebuilt file holds your sheets and their names, cell values, formulas, and number formats — so a date column comes back as dates rather than five-digit serial numbers, and a total still says =SUM(D2:D40).

It does not hold charts, images, pivot tables, slicers, macros, comments, colours or column widths. That is a deliberate trade, not an oversight: those parts live elsewhere in the package, and in a file this damaged they are either broken themselves or unreachable behind the damage. Recovering the data honestly beats handing back a workbook that looks complete and isn't.

Before you upload anything

1. Work on a copy. Always, with any repair tool. Keep the damaged original untouched somewhere — a second attempt with a different tool needs the same bytes you started with.
2. Check it isn't just blocked. A file downloaded from email or the web gets marked by Windows, and Excel then refuses it in a way that looks like damage. Right-click → Properties → Unblock, and try again.
3. Try Excel's own repair. File → Open → Browse, pick the file, then the arrow beside Open → Open and Repair. It handles some faults this tool doesn't, and the two are worth trying in either order.
4. Look for the autosave copy. Excel keeps unsaved versions under File → Info → Manage Workbook, and Windows keeps previous versions of a file under Properties → Previous Versions. Either may be newer than what you can recover.

Is my file private?

It's read on the server to be diagnosed and rebuilt, then deleted within the hour by a sweep that runs whether or not you come back. Nobody opens it, and nothing from inside it is stored — the usage log keeps the tool name, the file size, and nothing else.

Other tools that might be what you need

• Password Protect Excel — if the workbook is encrypted rather than damaged, take the password off there and it will open normally.
• Detect Anomalies — once the file opens again, check whether the data inside it survived intact.
• Compare Excel Files — put the recovered workbook next to an older backup and see exactly what the damage cost you.