To password protect a Word document, you use Word’s built‑in Encrypt with Password feature, which forces anyone who opens the file to enter a password first.

How it works in a nutshell

When you add a password in Word, the file itself is encrypted, so it can’t be opened without that password. This is different from just making it read‑only or “mark as final,” which only discourages editing but doesn’t truly secure the content.

Step‑by‑step: Windows (Microsoft 365 / 2019 / 2021)

  1. Open your Word document.
  1. Click File in the top‑left.
  1. Select Info in the left menu.
  1. Click Protect Document.
  1. Choose Encrypt with Password from the dropdown.
  1. Type your password when the box appears, then click OK.
  1. Type the same password again to confirm and click OK.
  1. Save the document so the password protection takes effect.

After this, anyone trying to open the file will be prompted for the password first.

Step‑by‑step: Mac (Word for Microsoft 365 / 2021)

  1. Open your document in Word for Mac.
  1. Go to the Review tab on the ribbon.
  1. Click Protect , then choose Protect Document.
  1. Select Encrypt with Password.
  1. Enter your chosen password, then confirm it when asked.
  1. Save the document to apply the protection.

The behavior is the same: the file requires the password before it opens.

Word for the web (online) limitations

  • Word for the web (browser version) does not let you add an open‑password directly in the online editor.
  • To password protect a document stored in OneDrive/SharePoint, you typically:
    • Open it in the desktop Word app, then use Encrypt with Password , or
    • Control access using sharing permissions (who can open the file) instead of a document‑level password.

Important tips and caveats

  • Password length and case: Office’s traditional password encryption supports passwords up to 15 characters and treats uppercase and lowercase as different characters (“Password” ≠ “password”).
  • No recovery if you forget it: If you lose the password, Word itself cannot recover it; the document may be permanently inaccessible. In some business setups, IT admins can use a special DocRecrypt tool, but only if it was configured before the password was added.
  • Strength of password: Use a mix of upper‑ and lower‑case letters, numbers, and symbols to make guessing harder.
  • Sharing risk: Even with encryption, anyone who legitimately has the password can forward both file and password to others.

Extra protection options in Word

Beyond a password to open, Word also offers other protection controls:

  • Restrict Editing: Make the document read‑only or allow only tracked changes, comments, or filling in forms.
  • Mark as Final: Flags the document as finished and discourages editing, but doesn’t truly secure it.
  • Digital signatures & advanced encryption: Available via File > Info > Protect Document, for authenticity and stronger security in some environments.

These can be combined with a password to open for layered protection.

If you want even stronger or more shareable protection

Some guides suggest converting your Word file to a secured PDF, which can use robust encryption and is easier to share without changing formatting. Tools and services (including Microsoft’s own PDF export and third‑party utilities) let you lock the PDF so it requires a password and can restrict printing or copying.

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Learn how to password protect a Word document on Windows and Mac using Encrypt with Password, plus tips, limitations of Word online, and when to use PDFs for stronger security.

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