User Guide
Add the PDF
Encryption is applied in your browser. The document is never uploaded, which matters rather a lot for the files people choose to protect.
Understand the two passwords
A user password is needed to open the document at all. An owner password leaves it openable but locks the permissions. They do different jobs and you can set either or both.
Start from a preset
View Only blocks everything. + Print allows printing. Forms allows filling fields. All permits everything, None nothing. Presets are a starting point, not a limit.
Adjust the seven permissions
Printing, copying, modifying, annotating, filling forms, content accessibility and document assembly are each controlled separately. Set exactly the combination you need.
Leave accessibility enabled
Content accessibility is what lets a screen reader read the document aloud. Disabling it locks out blind and partially sighted readers while stopping almost nobody else — it is rarely the right choice.
Save the password somewhere
There is no recovery. A user password you cannot remember means a document you cannot open, by design. Store it before you close the tab.
About the Secure PDF Tool
This tool encrypts a PDF and sets what a reader is permitted to do with it. Both the encryption and the permission flags are applied in your browser — the document is never transmitted.
Two passwords that do different things
PDF has always had two, and confusing them is the most common mistake.
The user password (sometimes “open password”) is required to view the document at all. Without it, the file is unreadable. This is real protection: the content is encrypted, not merely hidden.
The owner password (sometimes “permissions password”) leaves the document open to anyone but locks the settings that say what may be done with it. Readers can see it; they cannot change what they are allowed to do.
Set a user password when the content itself is confidential. Set an owner password when the content is meant to be read but not reused. Set both when a document is confidential and should not be copied by the people entitled to read it.
The seven permissions
| Permission | Controls | Typical use |
|---|---|---|
| Printing | Sending to a printer or PDF writer | Off for screen-only distribution |
| Copying | Selecting and copying text | Off to discourage lifting content |
| Modifying | Editing the content | Off on anything signed or final |
| Annotating | Adding comments and highlights | On for documents under review |
| Filling forms | Entering data in form fields | On for anything meant to be completed |
| Content accessibility | Screen readers reading aloud | Leave on — see below |
| Document assembly | Inserting, deleting, rotating pages | Off on fixed-order bundles |
The accessibility flag deserves its own sentence. It exists so that assistive software can read a document to someone who cannot see it. Turning it off does not meaningfully stop copying — anyone determined has other routes — but it does make the document unusable for blind readers. In several jurisdictions disabling it on a document offered to the public is a compliance problem. Leave it enabled unless you have a specific reason not to.
What permissions actually enforce
Being straight about this matters. The user password is genuine encryption — without it, the bytes cannot be read.
The permission flags are different. They are instructions stored in the file, and they are honoured by well-behaved readers: Acrobat, Preview, most browsers, most mobile viewers. They are not enforced by mathematics. Software that chooses to ignore them can, and some does.
So permissions are the right tool for making the intended use clear and preventing casual copying by ordinary users. They are not the right tool against a determined adversary. If a document must not be extracted under any circumstances, do not distribute it as a PDF.
Losing the password
There is no recovery and no back door. That is the point of encryption — a mechanism for getting in without the password would be a mechanism for anyone getting in without the password. Record it before you close the page.
If you need to remove protection from a document whose password you do have, the Unlock PDF tool does that.
Frequently Asked Questions
What is the difference between the two passwords?
A user password is needed to open the document at all — that is real encryption. An owner password lets anyone open it but locks the permission settings. Use the first for confidential content, the second for content meant to be read but not reused.
Can the permissions actually be enforced?
The user password can — without it the file cannot be decrypted. Permissions are instructions that well-behaved readers honour; software that chooses to ignore them can. They stop casual copying, not a determined adversary.
Should I disable content accessibility?
Almost never. That flag is what allows screen readers to read the document to blind and partially sighted people. Turning it off blocks them while barely inconveniencing anyone else, and in some jurisdictions it is a compliance problem.
What if I forget the password?
The document cannot be opened, and there is no recovery. A back door for you would be a back door for everyone. Save the password before closing the page.
Is my document uploaded to be encrypted?
No. Encryption and the permission flags are applied in your browser, which matters given the kind of files people choose to protect.
Can I stop someone taking a screenshot?
No, and no PDF tool can. Permissions govern what a PDF reader will do; they have no reach over the operating system or a camera pointed at the screen.
Which preset should I start from?
View Only for documents to be read and nothing else. + Print when a paper copy is expected. Forms for anything to be completed and returned. Then adjust the individual permissions — the presets are a starting point.
How do I remove protection later?
Use the Unlock PDF tool, which removes encryption from a document when you supply the password. It cannot open one whose password you do not have.
