Short answer: in Word, Excel and PowerPoint for Windows go to File → Info → Protect Document / Protect Workbook / Protect Presentation → Encrypt with Password, type the password twice and save. On a Mac use Review → Protect (or File → Passwords, depending on the version) and set a password to open. This encrypts the file with AES; without the password it cannot be opened – and Microsoft cannot recover a lost password.
WordExcelPowerPointBeyond a password
Word: password to open a document
- Open the document and choose File → Info → Protect Document → Encrypt with Password.
- Type a password, confirm it, and save the file.
- To remove it later: the same menu, delete the password, save.
Not the same thing: Restrict Editing (Review tab) and Mark as Final do not encrypt – anyone can open the file, and both can be switched off by the reader.
Excel: password to open a workbook
- File → Info → Protect Workbook → Encrypt with Password, type and confirm the password, save.
- Optionally also set File → Save As → Tools → General Options → Password to modify, so others can open but not save changes.
Excel has three different "protects": Encrypt with Password (the only one that stops opening), Protect Workbook structure (stops adding or deleting sheets) and Protect Sheet (locks cells). The last two are for preventing accidental edits – they are easy to remove and are not security.
PowerPoint: password to open a presentation
- File → Info → Protect Presentation → Encrypt with Password, type and confirm the password, save.
- For a "password to modify": File → Save As → Tools → General Options.
Keynote and Google Slides cannot open an encrypted .pptx without the password either, so the protection travels with the file whatever app the recipient uses.
What a password does not protect
Encryption decides who can open the file. It does nothing once it is open:
- The password usually travels in the same e-mail or chat as the file, so whoever gets one gets both.
- The recipient can save an unprotected copy, forward it, print it or copy the content.
- You cannot take it back, change it after sending, or see whether it was opened.
When those matter – a price list, a financial model, a board deck – share the file as a link instead. In HelpRange you upload the .docx, .xlsx or .pptx and send a link: readers confirm their e-mail with a code (or enter a passcode), the file opens in the browser with download and print blocked, every page carries the reader's e-mail as a watermark, and you can revoke access or replace the file after sending. Pro is $39 per team per month; for a single PDF there is also our free password-protect-PDF tool.
FAQ
How do I password-protect a Word document?
File → Info → Protect Document → Encrypt with Password, type the password twice and save. On a Mac: Review → Protect Document (or File → Passwords) and set a password to open.
How do I password-protect an Excel file?
File → Info → Protect Workbook → Encrypt with Password. Protect Sheet and Protect Workbook structure only lock editing; they do not stop anyone opening the file.
How do I password-protect a PowerPoint presentation?
File → Info → Protect Presentation → Encrypt with Password, then save. A password to modify is under File → Save As → Tools → General Options.
Can a forgotten Office password be recovered?
No. Microsoft cannot recover it, and modern Office files use AES encryption, so keep the password in a password manager.
Can I password-protect a Google Doc, Sheet or Slides file?
No – Google files have no open password. You control access with sharing settings, or export to Office or PDF and protect that file.
More Office guides: password-protect Word, Excel or PowerPoint · protect Office files from copying · prevent forwarding · disable downloading from a website · best platforms for sharing Office files · free tool: share an Excel file online