How to Add a Password to a PDF File
You have a PDF you need to protect before sharing. Here is how to add a password on every platform — in under two minutes, for free.
The fastest method: online (works on any device)
Step 1: Go to quicktoolshub.org/lock-pdf
Step 2: Drop your PDF or click to browse
Step 3: Enter your password (and confirm it)
Step 4: Click “Lock PDF” and download the protected file
Total time: about 20 seconds. Works on Windows, Mac, iPhone, Android — no install required.
On Mac: using Preview
- Open the PDF in Preview (double-click, or right-click > Open With > Preview)
- Click File > Export as PDF
- Click the Security Options… button
- Check “Require password to open document” and enter your password
- Click OK, then Save
On Windows: using LibreOffice (free)
- Download and install LibreOffice from libreoffice.org (it's free)
- Open LibreOffice Draw (Start menu > LibreOffice Draw)
- Open your PDF: File > Open
- Export with password: File > Export as PDF
- Click the Security tab
- Enter a password in the “Open password” field and click Export
On Windows: if you created the PDF from Word
If the original document is a Word file (.docx): open it in Word, go to File > Export > Create PDF/XPS, click Options, check “Encrypt the document with a password”, enter your password, and click OK then Publish.
Choosing a good password
A long, random password is far harder to crack than a short one. Aim for at least 12 characters, mixing letters, numbers, and symbols. Avoid common words, names, or dates. Store the password in a password manager — if you forget it, the PDF cannot be opened.
Add a password to your PDF now
Upload, set a password, download. No sign-up, no server upload.
Use Lock PDF →Frequently asked questions
How do I add a password to a PDF?
The fastest way is to use an online PDF lock tool. Go to quicktoolshub.org/lock-pdf, upload the PDF, set a password, and download the protected file. Alternatively, use Preview on Mac (File > Export as PDF > Security Options) or LibreOffice on Windows/Mac/Linux (File > Export as PDF > Security tab).
Can I add a password to a PDF without Acrobat?
Yes. Adobe Acrobat is not required. Free options include: browser-based tools (no install), Preview on Mac (built-in), LibreOffice Draw (free download), and Microsoft Word when exporting to PDF. All produce standard encrypted PDFs compatible with every PDF reader.
How do I add a password to a PDF on Windows 10 or 11?
Windows does not have a built-in PDF password tool. The easiest free options are: (1) Use quicktoolshub.org/lock-pdf in your browser — no install needed. (2) Install LibreOffice (free), open the PDF in LibreOffice Draw, and export with a password via File > Export as PDF > Security tab. (3) If you have Microsoft Office, export from Word with password protection.
How do I add a password to a PDF on a Mac?
Open the PDF in Preview. Go to File > Export as PDF. Click 'Security Options...' at the bottom of the dialog. Check 'Require password to open document' and enter your password. Click OK and save. This uses macOS's built-in PDF encryption and requires no additional software.
Does adding a password affect the PDF quality or content?
No. Encrypting a PDF only adds an encryption layer around the existing content — the text, images, and formatting are unchanged. The file may be slightly larger (a few hundred bytes for the encryption metadata), but the content is identical to the original once opened with the correct password.
Can I add a password to a PDF on iPhone or Android?
Yes. Open Safari or Chrome on your phone and go to quicktoolshub.org/lock-pdf. Select the PDF from your Files app, enter a password, and download the protected version. This works on both iOS and Android without any app install.