Security

Protect PDF

Add AES-256 encryption to your PDF so that anyone who opens it must enter a password. Set a user password (required to open), an optional owner password (controls editing and printing permissions), and fine-grained permissions such as allowing printing but preventing copying. Uses the pdf-lib encryption API. Your file never leaves your browser.

  • Files never leave your device
  • Runs entirely in your browser
  • Free, no account needed
Use Protect PDF - free

How this works in your browser

Encryption is applied to the document in your browser before it is written out, using the PDF specification's own encryption scheme rather than a wrapper around the file. Two separate credentials are set: a user password, which the reader must supply before the content can be decrypted at all, and an owner password, which carries the permission flags. The asymmetry matters. Content behind a user password is genuinely encrypted, so it cannot be read without the key. Permission flags are stored in the document and rely on the viewing application to respect them, which most mainstream readers do but nothing forces. Because all of this runs locally, neither the file nor the passwords are transmitted anywhere.

Protect PDF vs. traditional online converters

FeatureProtect PDF (in-browser)Traditional online converters
File upload requiredNo - never leaves your deviceYes - file is sent to a server
Processing queueNone - starts instantlyOften, especially at peak times
Watermark on outputNeverCommon on free plans
Usage limitsNone - free, unlimited useOften capped per day or file size
Works offline once loadedYes, for most toolsNo - requires a live connection
Account requiredNoOften, for anything beyond a trial

How to use Protect PDF

  1. 1

    Open the Protect PDF tool

    Go to tools.slaytic.com and open the Protect PDF tool. No sign-up or account required.

  2. 2

    Drop your PDF and set passwords

    Add a user password to control who can open the file, and optionally an owner password plus permission flags for printing, copying, annotating and form filling.

  3. 3

    Download the protected file

    The encrypted document is written in your browser and offered for download. Save the password somewhere safe first.

Common ways to use Protect PDF

Emailing a confidential document

Add an open password before sending a contract, payslip or medical record, so an intercepted or misdirected email does not expose the contents.

Distributing a document you do not want edited

Set permission flags to discourage copying and editing when sharing a proposal or report for review.

Meeting a handling requirement

Satisfy a client or employer policy that documents containing personal data must be password protected in transit.

Frequently asked questions

What encryption standard is used?

AES-256 - the same standard used by professional PDF tools and mandated for high-security document workflows. It is part of the PDF 1.7 specification.

Can I allow printing but prevent copying of text?

Yes. The owner password controls a set of permission flags including printing, content copying, annotation, and form filling. You can enable or disable each independently.

Can I remove the password later?

Yes - use the Unlock PDF tool and enter the password you set to produce an unencrypted copy.

What is the difference between the user and owner password?

The user password is the one someone must type to open the document at all, and it is the genuinely protective one. The owner password does not gate opening; it sets the permission flags for things like printing and copying. A file with only an owner password opens for anyone.

Can someone get around the printing or copying restrictions?

Yes, and it is important to understand this. Permission flags are instructions that well-behaved PDF readers choose to honour, not cryptographic locks. Software that ignores them can print or copy freely. Treat permissions as a clear signal of intent, and use a user password when the content genuinely must stay private.

What happens if I forget the password?

The document is not recoverable through this tool. There is no backdoor and no reset, which is the point of encryption. Store the password somewhere safe before you send the file.

Is my password sent anywhere?

No. Encryption happens inside your browser tab, so both the document and the password you type stay on your device.

Lock your PDF with AES-256 encryption - free, runs locally.

Open Protect PDF
  • Files never leave your device
  • No upload required
  • No account needed
  • Unlimited use, always free