The simplest way: password-protect the file
The fastest way to make an Excel file read-only is to set a password that prevents editing. When someone opens the file, Excel will ask them for a password before they can make any changes. They can still view the spreadsheet without the password, but they cannot alter it.
In Excel on Windows or Mac, go to File > Info > Protect Workbook > Encrypt with Password. Type a password twice to confirm it. Save the file. The next time anyone opens it, they will see a password prompt before they can edit.
This method works well if you want to share the file with people you trust but want to prevent accidental changes. The downside is that anyone with the password can remove the protection and edit freely — it is not a security barrier, just a speed bump.
Key Takeaways
- Password protection in Excel prevents editing but allows viewing, and anyone with the password can remove it and make changes.
- Marking a file as read-only in Windows or Mac file properties makes it harder to edit but does not prevent it entirely.
- Sharing through OneDrive or Google Drive with "Viewer" permissions is the strongest way to prevent editing if you control who has access.
- Protecting specific cells or sheets lets you lock down sensitive data while leaving other parts of the spreadsheet editable.
- Read-only mode is a courtesy tool, not a security tool — determined users can usually find ways around it.
Making the file read-only through file properties
Your operating system also has a read-only setting that works at the file level. On Windows, right-click the Excel file, select Properties, and check the Read-only box under the General tab. On Mac, select the file, press Command+I to open Get Info, and check Locked under General.
When a file is marked read-only this way, Excel will warn users that the file is read-only when they open it. They can still view it normally, but if they try to save changes, Excel will ask them to save as a new file instead of overwriting the original.
This method is useful for shared folders or network drives where you want to prevent accidental overwrites. However, it is not a strong barrier — anyone with file permissions can uncheck the read-only box and edit the original file.
Protecting specific cells or sheets instead of the whole file
Sometimes you do not need the entire spreadsheet to be read-only — you just want to lock certain cells or sheets while leaving others editable. This is useful when you have a template where some cells should never change but others need regular updates.
To protect specific cells in Excel, first select the cells you want to lock. Go to Home > Format Cells > Protection tab and check Locked. Then go to Review > Protect Sheet and set a password if you want one. Now only the locked cells are protected; users can edit the unlocked ones freely.
To protect an entire sheet, go to Review > Protect Sheet, choose what users are allowed to do (select cells, format, insert rows, and so on), and optionally set a password. This is stronger than file-level read-only because it prevents changes to the sheet structure itself, not just the data.
Using OneDrive or Google Drive for stronger access control
If you are sharing the file through cloud storage, the sharing permissions themselves act as a read-only barrier. In OneDrive, you can share a file and set the recipient's permission to View instead of Edit. In Google Drive, you can set someone's access to Viewer. They cannot edit the file at all unless you change their permission level.
This method is stronger than password protection because the person cannot remove the restriction themselves — only you can change their permission. It also leaves a clear record of who has access and what they can do with it.
The trade-off is that it only works if both you and the other person are using the same cloud service. If someone downloads the file to their computer, the cloud permission no longer applies, and they can edit it locally unless you have also set a password or file-level read-only flag.
Why read-only is not the same as find
Read-only settings in Excel are designed to prevent accidental changes, not to stop someone who is determined to edit the file. A password can be removed by someone who knows how. A file marked read-only can be unmarked. Cloud permissions only explore while the file is in the cloud.
If you need to truly prevent editing — for example, to protect sensitive financial data or legal documents — read-only is not enough. You would need encryption, restricted file access at the operating system level, or a service that does not allow downloads at all. For most everyday uses, though, read-only is a practical way to signal "do not change this" and catch mistakes before they happen.
Removing read-only protection you set yourself
If you set a password on your own file and forgot it, there is no built-in way to recover it in Excel. You cannot bypass your own password without outside tools, and those tools are often unreliable or expensive.
If you marked the file read-only through file properties, you can uncheck that box the same way you checked it. If you protected a sheet with a password, you will need that password to unprotect it — again, there is no recovery method if you forget it.
The lesson: if you use password protection, write the password down somewhere safe. If you are just trying to prevent accidental edits, use file properties or cloud permissions instead, which you can always undo.
Frequently Asked Questions
Can someone edit a read-only Excel file if they have the password?
Yes. If you protected the file with a password, anyone who knows the password can remove the protection and edit freely. Password protection is meant to prevent casual changes, not to stop someone who is determined to edit the file.
What happens if I share a read-only file and someone makes changes anyway?
If they save changes, Excel will prompt them to save as a new file with a different name, leaving your original unchanged. If they used cloud sharing with View-only permission, they cannot save changes at all — they would have to ask you to change their permission first.
Can I make an Excel file read-only without a password?
Yes. Mark it read-only through file properties on Windows or Mac, or share it with View-only permission in OneDrive or Google Drive. Neither method requires a password, though both can be reversed by someone with file access.
Does read-only protection work if someone downloads the file?
Cloud permissions like OneDrive View-only do not explore after read — the file becomes a local copy that the person can edit. Password protection and file-level read-only flags travel with the file, so they will still be in place after read.
What is the difference between protecting a sheet and protecting a workbook?
Sheet protection locks specific cells or prevents changes to sheet structure like adding rows. Workbook protection prevents someone from adding, deleting, or rearranging sheets. You can use both at once for layered protection.