How to protect and unprotect Excel sheet with or without password

What you need to know about Excel worksheet protection

Worksheet protection in Excel is not a security feature. It's is not actually intended to prevent people from accessing data in a password-protected worksheet. Why? Because Microsoft Excel uses a very simple encryption algorithm for worksheet protection. Even when you protect your Excel worksheet with a password, that password is very easy to break.

In older versions (below Microsoft Excel 2010), it doesn't even matter how long and complex your password is. Anyone who has at least some basic knowledge of VBA can crack it in minutes (here's an example of the VBA code that easily cracks passwords in Excel 2010 and lower).

The recent versions of Excel use more sophisticated methods of sheet protection, but they are also vulnerable and can be unlocked without knowing a password. In other words, if someone really wants to get access to a protected sheet, they will.

So, does this mean that Excel worksheet protection is absolutely pointless? Not at all! It makes sense to lock Excel sheets to avoid accidental changes in the sheet contents. A common example is Locking formula cells to prevent inadvertent erasure or modification of formulas.

The bottom line is - lock an Excel spreadsheet to prevent other users from accidentally tampering with your data, but never store sensitive information in your Excel sheets.

If you strive to ensure the maximum security protection for your Excel files, be sure to do all of the following:

1. Use the modern versions of Excel with enhanced data encryption mechanisms.
2. Protect your sheets with strong passwords that include different types of alpha numeric characters and special symbols. At that, try to make passwords as random as possible, for example by using our password generating tool.
3. Protect the workbook structure to prevent other people from adding, moving, renaming, deleting or unhiding your sheets.
4. For workbook-level security, encrypt the workbook with different passwords from opening and modifying.
5. If possible, store your Excel files with sensitive information in a secure location, e.g. on an encrypted hard drive.

How to protect Excel sheet

To protect a sheet in Excel, perform the following steps.

1. Right click a worksheet tab at the bottom of your screen and select Protect Sheet… from the context menu.

   Or, click the Protect Sheet button on the Review tab, in the Changes group.

2. In the Protect Sheet dialog window, do the following:
   • To password protect your Excel sheet, type a password in the corresponding field. Be sure to remember the password or store it in a safe location because you will need it later to unprotect the sheet.
   • If the worksheet protection is nothing more than a precaution against accidental modification of the sheet contents by yourself or by the members of your local team, you may not want to bother about memorizing the password and leave the password field empty. In this case, unprotecting the sheet takes just a single click on the Unprotect Sheet button on the ribbon or in the sheet tab's right-click menu.
   • Select the actions you allow the users to perform.
     • By default, the following 2 options are selected: Select locked cells and Select unlocked cells. If you leave only these two options selected, the users of your sheet, including yourself, will be able only to select cells (both locked and unlocked).
     • To allow some other actions such as sorting, filtering, formatting cells, deleting or inserting rows and columns, check the corresponding boxes.
     • If you don't check any action, users will only be able to view the contents of your Excel sheet.
   • Click the OK button.
   
3. The Confirm Password dialog box will pop-up prompting you to retype the password so that an accidental misprint won't lock your Excel sheet forever. Retype the password and click OK. Done!

How to unprotect Excel sheet

As you have just seen, it's very easy to password protect a sheet in Excel. Unprotecting a spreadsheet is even easier, provided that you know the password. Though, unlocking an Excel spreadsheet without password is no big deal either :)

How to protect a workbook in Excel

Apart from protecting the sheet contents, you may also want lock the entire workbook to prevent users from adding, moving, renaming or deleting worksheets, and viewing hidden sheets.

To protect the workbook, perform the following steps:

1. On the Review tab, in the Changes group, click the Protect Workbook button.
2. Under Protect workbook for, select one of the two options, or both:
   • Check the Structure box to protect the structure of a workbook. This will prevent the following actions:
     • Viewing hidden worksheets.
     • Renaming, moving, hiding or deleting sheets.
     • Inserting new sheets and chart sheets. However, users will be able to insert a chart in an existing worksheet.
     • Moving or copying sheets to another workbook.
   • Check the Windows box to retain the size and position of workbook windows. This will prevent users from moving, resizing, minimizing, or closing the workbook windows.

     Note. The Windows option is not available (greyed out) in Excel 2013 and higher, as shown in the screenshot above. It is because Microsoft introduced the Single Document Interface in Excel 2013, where each workbook has its own top-level window that can be minimized, restored, and closed.

3. In the Password box, type a password, and click the OK button.
   As indicated on the dialog window, a password is optional. However, if you do not enter a password, then anybody will be able to unlock your workbook with a button click.
4. Retype the password in the Confirm Password window and click OK. That's it!