What is Protect PDF and how does it work?

Protect PDF adds a password to a PDF so it can't be opened without it. You can also restrict printing, copying and editing, so the document can be read but not reused.

How do I use Protect PDF online?

Upload your file using the box above — drag it in, browse for it, or bring it in from your cloud storage. A preview appears so you can check you've picked the right file. Run Protect PDF, then download the result. You can rename it before you save it.

Is my file secure when I use Protect PDF?

Yes. The file you send to Protect PDF travels over an encrypted HTTPS connection and is processed automatically on our servers. It is never made public, never shared with anyone, and nobody reads it.

Does HuntPDF store my files after Protect PDF has run?

No. Your upload is deleted the moment Protect PDF finishes with it, and the file it produces is removed as soon as you have downloaded it, or when you upload another file, or when you close the page. Nothing is kept, and nothing is used to train anything.

Will the original quality and formatting be maintained?

Yes. Adding a password doesn't alter a single page — the content is identical, it's just locked.

Can I use Protect PDF on mobile?

Yes. Protect PDF works in any modern browser on phones and tablets — iPhone, iPad or Android — with nothing to install. You can upload straight from your device or from your cloud storage.

Can I rename my file before downloading it from Protect PDF?

Yes. The file Protect PDF gives you back keeps the name of the file you uploaded by default. If you'd rather call it something else, edit the name in the field next to the download button before you save it.

Do I need to install any software to use Protect PDF?

No. There is nothing to download, install or sign up for — Protect PDF is used from your browser and does the work on our servers, so it behaves the same on Windows, macOS, Linux, Android and iOS.

How long does Protect PDF take?

Most files are finished in a few seconds. A large or page-heavy file takes a little longer, because Protect PDF runs on our servers rather than on your device — but you won't be waiting around. You can upload files up to 250MB.

Is Protect PDF free to use?

Yes. Protect PDF is free, with no signup, no watermark on the result and no daily limit for normal use.

Can I remove the password from a protected PDF later?

Yes, as long as you know it. Unlock PDF removes the password, or lets you change it to a new one.

Does Protect PDF change the content?

No. The pages, text and images stay the same; the file simply asks for the password before it opens.

What can I stop people doing in Protect PDF?

Printing, copying text and images, editing pages, and commenting or filling in forms. Each has its own switch.

What if I forget the password?

It cannot be recovered, so keep the original unprotected file or store the password somewhere you will find it.

What is the shortest password I can use?

At least four characters, though a longer passphrase is much harder to guess.

My PDF already has restrictions. What happens?

The tool spots them and tells you. Protecting the file again replaces the old restrictions with the ones you choose.

Protect & Unlock PDF Online – Free, No Signup

Drop your file on the target

Several files · up to 260 MB each · deleted after processing

Drop your file here

Choose file

AES-256 encryption
Choose what people can do
Up to 260 MB per file

Processed on our secure servers over HTTPS. Your files are deleted automatically after processing.

Protect PDF adds a password to a PDF, so nobody can open it without typing that password, and lets you decide whether people can print, copy or edit it once it is open. An accountant might do this before emailing a client's tax return, and an HR team before sending out payslips.

How to use Protect PDF

Add your PDF from your device, Google Drive, Dropbox or OneDrive, up to 260 MB. Type a password, then type it again to confirm. A meter shows whether it is Weak, Good or Strong, and Show password lets you check for typos. Press Protect PDF and download the protected file, or send it on with Continue with this file.

Protect PDF options

Under Encryption you can keep AES-256, the default, or choose AES-128 if the file has to open in a very old PDF reader. Below that, four switches set what people can do once the file is open: Print, Copy text & images, Edit pages, and Comment & fill forms.

Out of the box, printing and commenting are allowed while copying and editing are off. That suits a document someone needs to read, print and sign but not change, such as a lease a landlord sends to a new tenant.

Choosing a password you can share

Pick something hard to guess but easy to pass on: three or four unrelated words are simpler to read out over the phone than a random string. Send the password by a different route from the file, such as a text message. Keep a note of it too, because a forgotten password cannot be recovered.

Frequently asked questions

Can I remove the password from a protected PDF later?: Yes, as long as you know it. Unlock PDF removes the password, or lets you change it to a new one.
Does Protect PDF change the content?: No. The pages, text and images stay the same; the file simply asks for the password before it opens.
What can I stop people doing in Protect PDF?: Printing, copying text and images, editing pages, and commenting or filling in forms. Each has its own switch.
What if I forget the password?: It cannot be recovered, so keep the original unprotected file or store the password somewhere you will find it.
What is the shortest password I can use?: At least four characters, though a longer passphrase is much harder to guess.
My PDF already has restrictions. What happens?: The tool spots them and tells you. Protecting the file again replaces the old restrictions with the ones you choose.