PDFLosslessRuns in your browser

Protect PDF

Add a password to a PDF so only people you tell can open it — AES-256, set in your browser. The conversion is lossless — every pixel, sample or byte in the source is preserved.

Not uploaded to any serverConverted on this deviceGone when you close the tabHow this works

Drop your files here

PDF · up to 200 MB each

or paste files from your clipboard

Ready when you are

Add a password to a PDF so only people you tell can open it — AES-256, set in your browser. Everything happens in this tab; nothing is sent anywhere.

⌘K to search converters

How to use it

1
Add your files
Protect PDF works with PDF. Drop them in, browse for them, or paste from your clipboard.
2
Choose your options
Tune the output settings — or leave the defaults, which are sensible.
3
Run it and download
Press the button and save the result. Everything happens on your device, and nothing is uploaded.

Privacy, in plain words

Is it safe? Your PDF is not uploaded anywhere

What “uploaded” normally means. On most online converters, pressing the button copies your file across the internet onto a computer owned by that website. That copy is what the word “upload” means, and it is the part nobody explains.

What happens instead. This site does not do it. There is no server here that receives files, so your PDF is read, converted and handed back by the browser you are using right now. It never travels — so there is no copy to store, read, leak or hand over.

Check it yourself in ten seconds

Turn off your Wi-Fi after this page has loaded, then convert a file anyway. It still works, because everything needed is already on your device.

The longer explanation of how this works, and the full detail of what is and is not stored on the privacy page.

Why this matters more than it sounds

PDF is the format people use for exactly the documents they would not hand to a stranger. It matters more than it sounds, because of what PDFs usually are:

Signed contracts

your signature, and terms you may be under NDA about

Tax returns

income, dependants, tax file or social security numbers

Passport and visa scans

the single most useful document for identity theft

Medical letters and results

a diagnosis is not something to leave on a server

A file that is never sent cannot be kept, leaked, subpoenaed or used to train anything. That is a property of how this works, not a promise about how carefully it is run.

What a PDF password actually does

Protecting a PDF encrypts its contents — the text, the images, the fonts — with a key derived from your password. Without the password the file is unreadable noise; with it, any PDF reader opens it normally. This uses AES-256, the strongest encryption the PDF standard defines and the one every current reader supports.

PDFs actually carry two passwords. The one you set here is the open password, which is what people usually mean. The second, the owner password, guards permissions such as printing and copying text. If you leave it empty a long random one is created, so the permissions you choose cannot be lifted by someone who only knows the open password.

Nothing is uploaded: The encryption happens in this tab. Your password and your document never reach a server, which is the point of protecting them.
Lose it and it is gone: There is no recovery. Strong encryption cannot have a back door for the owner without having one for everyone else, so keep the password somewhere safe.
Permissions are a request: ‘No printing’ and ‘no copying’ are honoured by mainstream readers, but they are rules the reader agrees to follow, not encryption. The open password is the part that actually keeps people out.

About these formats

Accepts

Portable Document Format

Fixed-layout documents that look identical everywhere.

Extensions: .pdf
MIME type: application/pdf
Best for: Sharing documents · Printing · Contracts and forms
Compatibility: Universal.

Encrypted with AES-256, the strongest PDF encryption. Your password never leaves this tab, and it cannot be recovered if you lose it.

Good to know

Protect PDF — questions

How does Protect PDF work?

Add a password to a PDF so only people you tell can open it — AES-256, set in your browser. Add your files above, adjust anything you want to change, and press the button. The result downloads straight to your device.

Is there anything I should watch out for?

Encrypted with AES-256, the strongest PDF encryption. Your password never leaves this tab, and it cannot be recovered if you lose it.

Is Protect PDF safe — are my files uploaded to a server?

No, nothing is uploaded. On most online tools, pressing the button copies your file across the internet onto a computer owned by that website, where it is processed and then sent back. That copy is what "upload" means. This tool does not do it: your file is read and processed by the browser you are using right now, stays on this device the whole time, and is discarded when you close the tab. Turn off your Wi-Fi after the page loads and it still works, which is the quickest way to confirm it.

Can I use this on confidential or personal documents?

Yes — that is the case it was built for. Because the file never leaves your device, a confidential document is no more exposed than it is sitting in your own folder: there is no transfer, no copy on anybody else's hardware, no retention period and no staff with access. Nothing about the file is logged either — not its name, not its size, not its contents.