Updated October 14th, 2020.
You can password-protect any Excel document, so even if people have access to your computer they won’t be able to get into your private documents.
There are lots of Excel documents you might want to keep private: spreadsheets with financial information, a Christmas gift list, people you might have infected with COVID-19 at an ill-advised gathering at the Rose Garden.
These instructions are for Excel 16 (the one you’d get with Office 365 in the year 2020) but they’ll work for many older versions of Excel as well.
There are two ways to password-protect an Excel document on a Mac. They start out different but they end up the same.
- Via the Save As… box
- Via the File menu
Let’s take them in order
Password-protect a Mac Excel document via the Save As… box
You can set a password when you first save the document, or you can choose Save As… later and do it then. Either way, you’re going to see a box like this:
Click the Options button. That leads you to this window:
(Naturally, this method is completely different than the way you password-protect a document in Microsoft Word. If you want to know how to password-protect a Microsoft Word document, click here.)
If you set a password for opening the document you’ve really done all you need. You can probably come up with a situation where you’d want one password for opening the document and another one for editing but I think that situation would be unusual. Anyhow, enter a password for opening the document, click OK, and you’ll see this box:
Enter the password (this is to double-check that you really know what the password is) and you’re all set. From then on, double-clicking the document results in a box like this:
Enter the password and you’re in. Get it wrong and you’re kept out. Easy as pie. The password is stored in the document, so if you email the document to someone he’ll need to enter the password to open it up. (If you’re emailing the Excel document to someone it might make sense to give that person the password for opening it, but not for editing it.)
How to password-protect a Mac Excel document from the File menu
The other way to password-protect a Mac Excel document is via the File menu. With your spreadsheet open, go to the File menu and select Passwords…
Choosing Passwords… produces this box:
From here it’s the same as the Save As… method: enter passwords, confirm that you know it, and that’s that.
Please please please: whichever method you use, remember the password, because if you forget it, you’re sunk. I don’t know anyone who can hack into a locked Excel document– I don’t think it is possible. Maybe you should make a spreadsheet of passwords. Password-protect that one too.
Excel’s Help file doesn’t help
Interestingly, Excel’s instructions for password-protecting a document don’t work! If you open Excel’s Help file, and search for “protect” instructions you’ll quickly hit a dead-end, because their instructions are wrong. They tell you to click File/Info (in the Ribbon) but “File” doesn’t exist. Here’s a screenshot of the video showing you something you can’t do.
The File menu in the Mac’s menubar is not the same as the File tab in the Ribbon. The items under File in the menubar do not include “Info.” So right in Step 1, you’re sunk. Except now you know how to password-protect a document, using a method that works.
Note: if you try to use the Mac’s QuickLook feature in order to sneak a peak at a locked document, you’ll get this:
Sort of reassuring, isn’t it?