PDF Time Machine

Protected entirely in your browser

Password Protect PDF

Need to remove a password instead of adding one? Try our Remove PDF Password.

Add password protection to a PDF — set a password to secure PDF content like tax documents, contracts, or ID scans, anything you wouldn't want an unintended reader to open. Encrypt PDF online, entirely in your browser, and get back a protected document; the file and the password you set are processed entirely on your device, and neither one is ever uploaded anywhere.

This file never leaves your browser — no upload, no server, nothing sent anywhere.

How to password protect a PDF online

Add a password to a PDF in your browser — no software, no upload

Most online tools that let you password protect a PDF ask you to upload the exact document you're trying to secure — an odd trade-off when the whole point is keeping it away from other people's servers. This tool works differently: drop your file into the box above, set a password, and the encryption happens using your own browser's processing power. There's no account, no install, and no file sitting on a server anywhere in between. Whether you think of it as adding password protection to a PDF, choosing to encrypt PDF online rather than mail an unprotected copy, or just locking a file so only you can open it, the result is the same — a genuinely secured document, created without the document ever leaving your device.

Set a password once, and the PDF is encrypted everywhere it goes

Once you set a password here, it's baked into the file itself — not into a viewer, a link, or an account. Email the resulting PDF, put it on a USB drive, or upload it somewhere else entirely, and it stays encrypted and password-protected no matter where it ends up or who opens it. That's a meaningful difference from services that only "protect" a file while it's hosted on their own site (a shared link with a password gate, for example) — this produces an actual encrypted PDF document, recognized as such by any standard PDF reader, permanently.

AES-256: what a password-protected PDF actually means

Setting a password on a PDF here uses AES-256 — the current strongest revision of the PDF spec's built-in encryption, the same algorithm behind most modern disk encryption and secure messaging. The password you choose derives the actual encryption key; without it, the file's content is unreadable, not just hidden behind a login screen. That's the real distinction between an encrypted PDF and a merely locked one: a locked file can sometimes be opened by ignoring or stripping a restriction flag, but a properly encrypted PDF file has no readable content at all until the correct password derives the key needed to decrypt it.

Restrict printing, copying, and editing independently of the open password

Beyond the password required to open the file, you can optionally restrict what a reader is allowed to do once it's open — printing, copying text, editing content, filling form fields, or adding comments — each toggled independently in the Advanced section. Under the hood, this assigns a second, internal password to the file (the "owner" password) that this tool generates and manages for you, so you never have to think about it separately. It's worth knowing upfront that these restrictions are honored by the PDF reader, not enforced cryptographically — the open password is what actually keeps the document unreadable to anyone who doesn't have it.

A real encrypted PDF, not a shared-link workaround

Some "protect my PDF" workflows just wrap a document in a password-gated download link instead of touching the file itself — convenient for a quick share, but the underlying PDF is still wide open the moment someone gets a copy of it directly. Creating an actually password-protected PDF file, the kind this tool produces, means the protection travels with the document permanently: rename it, move it, forward it as an attachment, and it still asks for the password before opening, with no separate service or link required to keep working.

Nothing leaves your browser, ever

Every step — reading the file, generating the encryption key, encrypting the content, and rebuilding the PDF — runs locally in a background thread inside your browser tab. Neither the file nor the password you set is ever uploaded, transmitted, or logged anywhere. That matters most for exactly the kind of document people usually need to protect: tax paperwork, signed contracts, medical records, ID scans — anything you'd rather not have pass through a third-party server, even briefly, on its way to being secured.

Frequently asked questions

How do I create a password protected PDF online for free?

Drop your file into the upload box above, type the password you want to set (and confirm it), then click Protect PDF — the encrypted, password-protected copy downloads a moment later. It's completely free, with no signup and no limit on how many files you protect, and "online" just means it runs on a web page: your file is encrypted locally in your browser, never uploaded to a server.

How do I add password protection to a PDF file?

Same process either way you phrase it: upload the PDF, choose a password, and optionally restrict printing, copying, or editing in the Advanced section. The tool assigns that password to the file using standard AES-256 encryption, so any PDF reader — not just this site — will ask for it before opening the file from then on.

What's the difference between the password and the permissions I can restrict?

The password (a 'user' password, in spec terms) controls whether the file can be opened at all — without it, a reader can't see any content. Permissions (governed by a separate, internal 'owner' password this tool generates for you) control what someone can do once the file is open, like printing or copying text. You only ever set the one password that matters: opening the file.

"Password protecting" a PDF vs. "encrypting" it — is there a difference?

Nothing meaningful for this tool — password-protecting a PDF works by encrypting it. "Encrypt," "secure," "lock," and "password protect" all describe the same underlying operation: the file's content is mathematically scrambled using a key derived from the password you set, and only that password can unscramble it again.

Why are permission restrictions a deterrent and not unbreakable security?

Permission restrictions are enforced by whichever PDF reader opens the file choosing to respect them — the same way a locked car door only works if people choose not to break the window. A reader that ignores the restriction flags can still extract content. The password required to open the file in the first place is real cryptographic protection; the printing/copying/editing toggles are a courtesy signal on top of it, not a second layer of encryption.

What encryption does this use, and why?

AES-256, the current strongest revision of PDF's standard security handler (R6) and the same algorithm used by TLS, disk encryption, and most modern security software. Since this is a new file being created (not compatibility with an old one), there's no reason to offer a weaker, older option.

Can I lock a PDF file with a password without installing any software?

Yes — there's nothing to download or install. The encryption runs using your browser's own built-in cryptography, the same technology behind HTTPS, so a modern browser is the only "software" involved. That also means it works identically on Windows, macOS, or a work computer where you can't install anything at all.

What happens if I forget the password I set?

Nothing can recover it. The password is never sent anywhere or stored by this tool — it exists only in your browser tab for the moment you use it, which is also why nobody else (including us) can help you get back into the file later. Write it down somewhere safe before you close this tab.

Is my file or password ever uploaded anywhere?

No. Both are processed entirely inside your browser tab, using your device's own processing power. Nothing is sent to a server, logged, or stored — closing the tab leaves no trace.