RunLocalTools

Password Protect or Unlock a PDF — Free, in Your Browser

Add a password to a PDF or remove one you already know, entirely in your browser. No upload, no account, no file size limits — and it’s completely free.

What it does

This tool does two things: it can lock a PDF behind a password so only someone who knows it can open the file, or it can remove a password from a PDF you’re already able to open. Both directions run entirely on your device — your file and your password are never sent anywhere.

How it works

Adding a password works by rebuilding your PDF as a set of high-resolution page images and then encrypting that new file with a standard PDF security handler — the same open, well-supported encryption format every major PDF reader understands. This is the only way to apply real password protection to an arbitrary PDF without a server: your browser can’t rewrite an existing PDF’s internal encryption in place, so it recreates the document from scratch and locks the copy. You can set a separate owner/permissions password and choose exactly what someone with just the open-password can still do — print, edit, copy text, or fill in forms.

Removing a password is smarter about preserving quality. The tool first tries a lossless method that strips the protection while keeping your original PDF’s real, selectable text and vector graphics completely untouched. It automatically checks that this worked correctly — comparing the unlocked page against the original — and only falls back to rebuilding the file as a high-resolution image copy if the lossless method can’t cleanly recover the content (this mainly affects PDFs locked with real open-passwords, since that kind of encryption can’t be reversed without decrypting each page). Either way, you’ll see which method was used before you download.

How to use it

  1. Choose Add password or Remove password at the top.
  2. Drop in your PDF.
  3. To add a password: type the password required to open the file (there’s a generator button if you want a strong random one), optionally set a separate permissions password, choose what’s allowed for printing/editing/copying/annotating, and pick a rendering resolution.
  4. To remove a password: if the file needs one to open, you’ll be prompted for it right there — the tool tells you plainly if it’s wrong.
  5. Review the result — a thumbnail preview and a note on whether your original text stayed selectable — then download.

FAQ

Will this work on any password-protected PDF? It can always remove a password once you supply the correct one, or tell you the file isn’t actually protected at all. Whether the output keeps selectable text depends on how the original file was encrypted — the tool always tells you which outcome you got.

Is the encryption here “real” security? Yes — the output uses a standard PDF security handler that any compliant reader (Acrobat, Preview, browsers, etc.) will honor. It’s the same class of protection most everyday PDF password tools use. For extremely sensitive documents where you need the strongest possible encryption, a dedicated desktop tool with AES-256 may still be worth using.

Why isn’t my text selectable after I added a password? Because your browser can’t encrypt an existing PDF’s content streams in place — the only way to lock an arbitrary file client-side is to turn each page into a sharp image first, then encrypt that. Visually nothing changes; searching/selecting text does stop working.

I forgot the password on my own file — can this help? No. This tool only removes a password you already know and enter yourself; it doesn’t guess, brute-force, or bypass passwords.

Does removing a password work if the PDF just has print/copy restrictions but no password to open it? Yes — the tool detects that automatically and strips the restrictions without asking you for anything.

Choosing a good password

If you’re setting a password rather than removing one, it’s worth using something you can’t guess your way into. Our password generator & strength checker is a fast way to get a genuinely random one — or check the strength of a password you already have in mind — before you lock the file.

Privacy

Nothing about your file or your password is ever uploaded or saved. This tool deliberately doesn’t remember your file between visits, unlike most of our other tools — for something you’re locking or unlocking, starting fresh each time is the safer default. If what you actually need is to permanently black out specific sensitive text or images rather than lock the whole document, our PDF redaction tool is built for that instead.