InfyTool
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Password-protect a PDF

AES-256 encryption applied on your own device — the PDF and the password never touch a server.

One PDF · encrypted with AES-256 on your device — the file and password never leave it

No size limit · files are processed on your device and never uploaded · how it works

Advanced settings (optional)
Password
New password

At least 4 characters. Typed and used only on your device — if you lose it, nobody (including us) can recover the file.

Confirm password
Permissions

Even with the password, viewers can be blocked from printing.

Runs in your browser. Files are never uploaded — you can go offline after the page loads.

How to use the Protect PDF (Password)

  1. Drop one PDF.
  2. Type a password (and confirm it) — optionally block printing.
  3. Download the AES-256-encrypted copy.

Easy to use

Drop files, pick options, download. Whole folders at once, no signup, no daily limit.

Best quality

The same engines the professionals use — SVGO, resvg, MozJPEG, libwebp, libavif — compiled to run in your browser.

Private & secure

Files are processed on your device and never uploaded. Close the tab and nothing remains anywhere.

Encryption that stays on your device

The strange ritual of most "protect PDF" sites is uploading a private document plus its new password to a stranger's server — the two things that should never travel together. Here the encryption itself runs in your browser: qpdf, the standard PDF toolkit, compiled to WebAssembly. The file and the password never cross the network, and you can switch off your Wi-Fi after the page loads to prove it.

The protection is real AES-256 — the same standard Acrobat applies — not a viewer-level nag. That cuts both ways: without the password the file is genuinely unreadable, so store the password somewhere safe. Need the reverse later? The Unlock PDF tool removes a password you know.

Frequently asked questions

Is this real encryption or just an “open” prompt?

Real encryption: the PDF content is encrypted with AES-256, the same standard Acrobat uses. Without the password the file is unreadable — there is no bypass. That also means a lost password cannot be recovered by anyone, including us.

Why does no-upload matter here especially?

Uploading a document plus its new password to someone’s server defeats the point of protecting it. Here qpdf runs as WebAssembly in your browser — nothing crosses the network, and you can go offline after the page loads.

Can I stop people printing the PDF?

Yes — untick “Allow printing” and viewers that honour PDF permissions will refuse to print it, even after entering the password.

Unlock PDF (Remove Password)Enter the password once, get a copy that opens without it Compress PDFScans and image-heavy PDFs shrunk hard Sign PDFDraw, type or upload your signature, click it onto the page, download Watermark ImagesYour name or brand across every photo

Your files never leave your device

Most online converters upload your file to a server. InfyTool ships the actual encoders to your browser as WebAssembly instead, so processing happens inside your tab — faster for batches, and nothing to delete afterwards.

  • No upload, ever. Turn off Wi-Fi after the page loads and every tool keeps working.
  • No limits. No file-size cap, no queue, no watermark, no account.
  • Runs on your CPU. Batches use several cores in parallel; nothing is throttled.

More free tools

Need icons or SVGs to start from?

InfyTool is built by the same team as these free libraries.

InfyIconFree SVG and PNG icons you can open directly in these tools. InfySVGFree SVG designs and illustrations, ready to optimise or convert. InfyPNGFree transparent PNG graphics for mockups and social posts.