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Protect PDF

Protect PDF is part of Toolspire and is ready as soon as this page loads. Lock a PDF with a password so only the people you choose can open it — and, if you like, stop printing, copying or editing. The file is encrypted on your device and not sent to us.

Runs in this tabFreeNo account

On this page

What you can do here

Strong encryption

AES-256 makes the contents unreadable without the password — not just hidden behind a prompt.

Permission controls

Allow reading but block printing, copying or editing — useful for question papers, drafts and price lists.

Password help

A strength meter shows how guessable your password is, and one click suggests a strong, memorable passphrase.

Verified output

Every file is re-opened with your password after encryption to make sure it works and no page is missing.

Many files at once

Protect a batch of salary slips, statements or certificates with the same password in one go.

Private by design

Unlike upload-based sites, your document and password are never sent anywhere.

The sequence

How to password-protect a PDF

  1. 1

    Add your PDF

    Drop one or more PDFs onto the box, or click to choose them.

  2. 2

    Set a password

    Type a password and confirm it, or click Suggest a strong one. Save it somewhere safe.

  3. 3

    Add restrictions (optional)

    Turn on Restrict printing, copying and editing and choose what to allow.

  4. 4

    Protect and download

    Click Protect PDF, then download the protected file or a ZIP of all of them.

Worth knowing

  • Protect PDF on Toolspire: encrypts PDFs with AES-256, the strongest standard PDF encryption, supported by Adobe Acrobat, Chrome, Edge, Firefox, macOS Preview and phone PDF apps (AES-128 is available for very old readers).
  • Optionally restrict printing (or allow low-quality printing only), copying text and images, editing, and comments or form filling.
  • Restrictions can be set with or without a password to open the file.
  • Each protected file is checked: it must ask for the password and still contain every page.
  • Protect several PDFs at once with the same password and download them as a ZIP.
  • Encryption runs in this tab with QPDF compiled to WebAssembly — the PDF and the password stay on this device.

Open password vs. permissions password

Open passwordPermissions password
What it doesEncrypts the file; nobody can view it without the passwordControls printing, copying and editing for people who open the file
StrengthStrong — the contents are unreadable without itA deterrent — respected by standard PDF apps, but not unbreakable
Use it forBank statements, IDs, salary slips, medical reportsDrafts, question papers, price lists you want read but not reused

Choosing a good PDF password

  • Use at least 12 characters — a few random words with a number, like Mango-River-Kite-7, is strong and easy to type.
  • Avoid names, birthdays, phone numbers and common passwords such as password123: they are the first things tried.
  • Send the password separately from the PDF — for example, the file by email and the password by phone or message.
  • Store it in a password manager. There is no “forgot password” for an encrypted PDF.
  • Need to open a protected PDF without the prompt later? Remove the password with the PDF Password Remover (you’ll need the password).

FAQ

Questions about Protect PDF

Where does Protect PDF run?

Protect PDF runs in this tab on Toolspire. What you type or drop in is not sent to us and is not stored on a server.

Is it safe to protect confidential PDFs here?

Yes. The PDF is encrypted in this tab, and neither the file nor the password is uploaded or stored anywhere.

What if I forget the password?

The PDF can’t be opened — by you, us or anyone else. That is what makes the encryption secure, so save the password somewhere safe before sharing the file.

Will the protected PDF open on phones?

Yes. AES-256 protected PDFs open in all current PDF apps on Android and iPhone, in browsers and in Adobe Acrobat, after entering the password.

Can I stop people from printing or copying my PDF?

Yes — turn on Restrict printing, copying and editing. Standard PDF apps respect these settings, but determined users with special software can bypass them, so don’t rely on restrictions alone for secrets.

Does adding a password change the PDF’s quality?

No. The pages, text and images are unchanged; only encryption is added. The file size stays almost the same.

Can I protect a PDF that already has a password?

Remove the existing password first with the PDF Password Remover, then protect it with the new one.

Is AES-256 better than AES-128?

Yes. AES-256 is the modern standard and supports passwords in any language. Choose AES-128 only for PDF readers older than about 2010.

Keep going

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