In Excel: go to File ▸ Info ▸ Protect Workbook ▸ Encrypt with Password, set a password, and the whole .xlsx then requires it to open.
On this page7
Open File ▸ Info, click Protect Workbook, and choose Encrypt with Password.
Type a strong password, click OK, then re-enter it to confirm.
Save the file (Ctrl+S) so the encryption is written to disk.
Test it by closing and reopening the workbook — it should prompt for the password before opening.
What this does
Encrypting a workbook with a password locks the entire file so it cannot even be opened without the password — the contents are scrambled on disk, not merely set to read-only. This is workbook-level (file-level) encryption, reached through File ▸ Info ▸ Protect Workbook ▸ Encrypt with Password, and it is completely separate from sheet protection: it controls who can open the file at all, rather than which cells can be edited once it is open. Before you run it on a workbook other people depend on, try it on a copy or a few rows first. Undo only reaches back through the current session, so a quick trial run is the cheapest way to see exactly what will change before the file is saved and shared. Treat “excel password protected file” as a small repeatable workflow rather than a one-off click you hope to remember next time. Use a small test block before the live file, so any surprise in the affected cells shows up while it is still harmless. When this is a ribbon command, the selection matters more than the button: confirm the range, apply the command, then spot-check the output before saving. That turns a workspace setting that makes a big sheet comfortable to navigate into a method you can reuse, explain, and defend when the workbook leaves your screen.
A worked example
You have a payroll workbook to email. Open File ▸ Info ▸ Protect Workbook ▸ Encrypt with Password, type a password such as Spr1ng!2026, confirm it, and save. The next time anyone — including you — double-clicks the .xlsx, Excel demands that password before it will display a single cell. Without it the file is unreadable; lose the password and there is no built-in way back in. Encrypt a workbook when the whole document is sensitive — salaries, contracts, personal data — and must not be readable by anyone who gets the file. It is the right tool when the goal is "nobody opens this without the password", as opposed to merely keeping a few formula cells from being overwritten. If this is something you do often, add the command to the Quick Access Toolbar (right-click it on the ribbon and choose Add to Quick Access Toolbar) or learn its shortcut, so next time it is one click instead of a hunt through the menus.
In Google Sheets
This is a command rather than a formula, so there is no syntax to carry over. Google Sheets arranges its commands in menus across the top instead of a ribbon, names some of them differently and does not have every Excel command — look for the equivalent in the Sheets menus or its help before assuming the steps match. Nothing on this page is behind a login or a download: the exact answer is at the top, and the detail below it is there for when you need it. That is the whole promise here — the answer first, and just enough context to make it stick. The short version of “excel password protected file”: the answer is at the top of this page, and the sections above explain why each step matters, so a variation of the problem does not stump you. Try it once on a copy of a real file and the steps stick far better than re-reading them.
Common mistakes
- Confusing this with Protect Sheet — encryption controls opening the file, not which cells can be edited.
- Losing the password: encrypted workbooks have no official recovery, so a forgotten password can mean permanent lockout.
- Assuming a read-only or "mark as final" setting is encryption — only Encrypt with Password actually scrambles the file.
- Relying on it for a shared OneDrive file where co-authoring expects an unencrypted document; encryption can block online editing.
Frequently asked questions
Is encrypting the file the same as protecting a sheet?
No. Encryption stops the file from opening without a password; sheet protection (Review ▸ Protect Sheet) lets the file open but locks certain cells from editing.
Can I remove the password later?
Yes — open the file with the password, return to File ▸ Info ▸ Protect Workbook ▸ Encrypt with Password, clear the password box, and save.
What if I forget the password?
There is no official Microsoft bypass for a forgotten open-password; the encryption is genuine, so always store it somewhere safe before you rely on it.
Other ways people ask this
On the way here you may have searched this as “how to crack a password protected excel file”, “how to unlock a password protected excel file” and “how to unprotect password protected excel file” — it is all the same task, and this page is the single, complete answer to it.
Why do people search for this in so many different ways?
Because the same task has many names. “how to crack a password protected excel file”, “how to unlock a password protected excel file”, “how to unprotect password protected excel file” all point at the one operation explained on this page, which is why they all lead here.