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Unlock a protected .xls file from old Excel

Why .xls is a different animal

Everything written about unlocking Excel sheets in the last fifteen years assumes an .xlsx: rename it to .zip, open xl/worksheets/sheet1.xml, delete a tag. That advice is correct, and it does not work on an .xls file at all.

A file saved by Excel 97–2003 uses BIFF8 records inside an OLE2 compound file — a binary container that predates the ZIP‑of‑XML format by a decade. There are no XML parts inside it and no folder structure to browse. Rename it to .zip and your archiver will just report a broken file. Sheet protection in that format is a binary record with a 16‑bit password hash, stored in a completely different place.

What happens if you drop an .xls on this tool

Being direct about it: this tool does not process .xls files. It reads the OOXML package, and an .xls is not one.

It also refuses the file with a message about file‑open encryption, which is misleading, and here is why. The tool checks the first eight bytes of whatever you give it. Encrypted Excel workbooks and legacy .xls workbooks share the same OLE2 signature, D0 CF 11 E0 A1 B1 1A E1, because encrypted OOXML files are wrapped in the very same old container. From the first eight bytes the two are indistinguishable, and refusing on the cautious reading is better than accepting a file it cannot repair. Convert first and the problem disappears.

Step 1 — convert the workbook to .xlsx

Sheet protection never stops you saving a copy in another format, so this works even though the sheet is locked:

Open the .xls in Excel. It will open normally — protection blocks editing, not opening.
File → Save As, and choose Excel Workbook (*.xlsx) from the format list. On a Mac the same option sits in the File Format dropdown of the Save dialog.
Save under a new name so the original stays intact.

If the workbook contains macros, pick Excel Macro‑Enabled Workbook (*.xlsm) instead — saving VBA code into a plain .xlsx silently discards it, and Excel warns you once before doing so.

No Excel to hand? LibreOffice Calc and Google Sheets both read .xls and can export .xlsx. Note that Google Sheets means uploading the workbook to Google, which may not be acceptable for the file in question.

Step 2 — remove the protection

The conversion carries the protection across: Excel translates the old binary protection record into a modern <sheetProtection> element in the new package. Your sheets are still locked, but now they are locked in a format that can be edited.

Drop the converted .xlsx or .xlsm onto the unlock tool.
The protection elements are stripped in your browser — the workbook is never uploaded — and you get an editable copy back.

If you would rather not convert at all and you still have the password, Review → Unprotect Sheet works on an .xls in any Excel version that can open it.

What the conversion changes

Going from .xls to .xlsx is normally uneventful, but it is a real format change and a few legacy things do not survive it:

Sheet size grows, it does not shrink. The old limit was 65,536 rows and 256 columns; the new format allows far more. Nothing is lost here.
Excel 4.0 (XLM) macro sheets are dropped. They are rare and mostly found in workbooks from the 1990s.
Very old chart and drawing objects are re‑rendered and can shift slightly.
VBA macros survive only if you save as .xlsm.

Excel’s own compatibility checker lists anything it intends to change before it saves, so read that dialog rather than dismissing it.

If the .xls will not even open

Everything above assumes the file opens and only editing is blocked. If Excel asks for a password before it will display the workbook, that is a file‑open password — the legacy format encrypted the workbook with RC4, later formats use AES. Either way the contents are genuinely encrypted, you cannot convert what you cannot open, and no tool here will remove it. Whether the password is a lock or a cipher is the whole question; telling the two apart takes about ten seconds.

Unlock it in seconds instead

The manual route works, but our free in‑browser tool does the same thing in one drop — nothing is uploaded, everything runs on your device.

Unlock your file now →

Frequently asked

Can I just rename my .xls to .xlsx?

No. Renaming changes the extension, not the contents. Excel will detect the mismatch and either refuse the file or warn that it is corrupt. You have to re-save through File → Save As so the data is genuinely rewritten in the new format.

Will converting to .xlsx break my formulas?

No. Formulas, values, formatting and named ranges convert directly. Only genuinely legacy features such as Excel 4.0 macro sheets are dropped, and the compatibility checker lists them first.

Does this tool support .xls at all?

No. It works on the OOXML package format used by .xlsx and .xlsm. A legacy .xls uses the older OLE2 container, which the tool does not read, so it will refuse the file rather than damage it.

What about .xlsb files?

An .xlsb is a binary workbook but it still uses the modern ZIP package, with binary parts instead of XML. Sheet protection is stored inside those binary parts, so the tool does not handle it either — re-save as .xlsx first, exactly as with .xls.