Password Protect a PDF for Free

FAQs about password protect PDF free.

• AES-128 vs AES-256: What is the difference?

  AES-128 and AES-256 are both encryption standards used to password protect a PDF document, ensuring that only authorized users can access or edit sensitive content. The main difference between AES-128 and AES-256 lies in the key length and the number of encryption rounds:
  AES-128 uses a 128-bit key and 10 rounds, while AES-256 employs a 256-bit key and 14 rounds. This means AES-256 offers a significantly higher level of security, making brute-force attacks virtually impossible with today’s technology, which is why it is often used for top-secret government and highly sensitive data. However, AES-128 is already extremely secure-requiring an astronomical amount of time and computational power to crack-and is generally faster and more efficient for everyday use.

  For those seeking a reliable and user-friendly solution, the PDFelement online PDF password protect tool is an excellent choice. It lets you easily set strong passwords and encrypt your PDF files with AES-256, providing both security and peace of mind. In summary, both AES-128 and AES-256 can be used to protect your PDFs, but AES-256 offers the highest level of security, while AES-128 is sufficient for most practical purposes and is widely supported by free online PDF lockers and protectors.

• How to send a PDF with password protection?
  1. Protect the PDF

     Use a trusted tool like PDFelement Online Password Protect tool, Adobe Acrobat to encrypt the file with a strong password.
     Tip: Use a mix of letters, numbers, and symbols (e.g., Fin@2025!Plan).

  2. Save the Secured File

     Once encrypted, save and label the file clearly (e.g., Q2_Report_PROTECTED.pdf).

  3. Share the File

     Attach to email or Upload to a secure cloud service (e.g., Dropbox, Google Drive with restricted access). Tip: If using a cloud link, ensure it has restricted access or an expiration date.

  4. Send the Password Seperately

     Never include the password in the same email. Instead, share it via:SMS, Phone call, Secure messaging apps (e.g., Signal, WhatsApp)

  5. Optional Extras

     Use tools that allow link expiration or QR sharing (PDFelement supports this).
     Set permissions to disable printing or copying if supported.

• How do you lock a PDF from editing?

  To prevent editing a PDF, you need to set permission restrictions—not just an open password. This is done by applying an owner password, which controls actions like editing, copying, \ or printing without restricting access for viewing.

  Tools to Lock PDF Editing:

  1. PDFelement (Desktop)
     • Go to Protect > Encrypt.
     • Set a permission password (also known as an owner password).
     • Choose which actions to restrict—editing, copying, printing, etc.
     • Supports AES-128, AES-256, and RC4 encryption.
     • Optional: Use redaction tools to permanently remove sensitive content.
  2. Adobe Acrobat Pro
     • Open the PDF and go to All Tools > Protect a PDF > Protect with Password.
     • Choose “Restrict Editing” and set a password.
     • Save the file to apply protection.
  3. Free Online Tools (e.g., PDF2Go, iLovePDF)
     • Upload your PDF.
     • Choose to set restrictions (editing, copying).
     • Apply a permission password and download the protected file.

  Note: Online tools are convenient but may offer weaker security than desktop apps.

• How to lock a PDF from copying?

  To lock a PDF from copying, you need to apply permission restrictions—specifically disabling the "content copying" permission using a permission (owner) password. Here’s how to do it with different tools:

  1. PDFelement (Desktop)
     • Open your PDF in PDFelement.
     • Go to Protect > Encrypt.
     • Enable Permission Password (also called Owner Password).
     • Uncheck "Enable copying of text, images and other content."
     • Save the file.

     Supports strong encryption: AES-128, AES-256, RC4.

  2. Adobe Acrobat Pro
     • Open the PDF.
     • Go to File > Protect Using Password.
     • Choose “Restrict editing and printing”.
     • Under Permissions, uncheck “Enable copying of text, images, and other content.”
     • Set a password and save.
  3. Free Online Tools

     Tools like PDF2Go, iLovePDF, or Sejda let you apply basic permission restrictions:

     • Upload your file.
     • Select “Restrict copying.”
     • Set a permission password.
     • Download the protected PDF.
• How to password protect a PDF on Mac?

  Password protecting a PDF on a Mac is simple, thanks to built-in tools and third-party software. Here’s how you can encrypt a PDF and lock editing in PDF files:

  1. Method 1: Using macOS Preview (Free & Built-In)
     1. Open the PDF in Preview.
     2. Click File > Export (or File > Export as PDF in newer macOS versions).
     3. Check the box for "Encrypt" and enter a password to protect the PDF.
     4. Save the file-now, anyone opening it will need the password.
  2. Method 2: Using Adobe Acrobat (Paid Option)

     If you need advanced security, Adobe Acrobat lets you:

     • Set owner passwords (to restrict printing/editing).
     • Apply permissions (like blocking copying text).
  3. Method 3: Online Tools (Free & Convenient)

     For a quick solution without software, try:

     • PDFelement’s online PDF password protect tool – Secures files in seconds.
     • PDF2Go or I Love PDF Password – Free web-based encryptors.
     • Online PDF locker services like Smallpdf or PDF2Go.

  By following these steps, you can easily password protect a PDF for free on Mac while keeping your documents secure from unauthorized copying or editing.

• How to protect PDF document with password in Adobe Reader?

  Adobe Reader (the free version) does not allow you to password-protect a PDF directly—you’ll need Adobe Acrobat Pro or an online tool to encrypt a PDF. However, you can still open and view password-protected files in Adobe Reader. Here’s how to secure a PDF if you have Acrobat Pro or alternative solutions:

  1. Method 1: Using Adobe Acrobat Pro (Paid)
     1. Open the PDF in Adobe Acrobat Pro (not Reader).
     2. Go to File > Protect Using Password (or Tools > Protect > Encrypt > Encrypt with Password).
     3. Choose:
        Require a password to open the document" (sets a user password).
        Restrict editing and printing" (sets an owner password to lock editing in PDF).
     4. Enter and confirm the password, then save the file.
  2. Method 2: Using Free Online Tools

     If you don’t have Acrobat Pro, try these free alternatives:

     • PDFelement's online PDF password protect tool-Simple and secure encryption.
     • iLovePDF Password Protect - Adds passwords without software.
     • PDF2Go - Lets you lock PDFs from copying/editing.

  For a quick, free way to password protect a PDF, online tools are the best choice if you don’t have Acrobat Pro. Otherwise, Adobe’s paid software provides the most control over permissions.

• Are there any limitations to PDFelement's online PDF editor?

  Yes, there are certain limitations for free users:

  Daily Usage Limits:

  · Most editing and conversion tools allow 1 free use per day (e.g., Edit PDF, Merge, Split, Compress, Convert, Protect).

  AI PDF Tool Limits:

  · Chat with PDF, AI Read, AI Proofreader:

  ①Limited to 10 uses

  ②Supports PDFs up to 100MB and 260 pages

  AI Translator & AI Detector:

  · Limited to 10 uses (every 10 pages = 1 use; under 10 pages still counts as 1 use)

  · Max file size: 100MB (AI Translator), 10MB (AI Detector)

  Note:

  · To enjoy unlimited usage, you can upgrade to premium access.

  Page/File Size Restrictions:

  · PDF files must be under 100MB (except for AI Detector)

  · Max file size for OCR: 50MB

  · Max 260 pages for AI tools