PDF security
What does Unlock PDF do?
Unlock PDF removes supported password encryption and many permission locks in the browser after you provide the authorized password. Visible pages and supported content are kept. Certificate-only authorization, DRM and some security actions cannot be removed here. Existing digital signatures become invalid when the file is rewritten.
How to use Unlock PDF
- 1Choose one PDF
Open Unlock PDF and select a single locked file. The tool accepts one PDF per task.
- 2Enter the authorized password
Type the current password if the file asks for one. Leave it blank only when the PDF already opens and you are removing remaining permission locks. You must be authorized to remove the protection.
- 3Remove supported locks locally
The browser decrypts supported RC4/AES password encryption and strips owner permissions, read-only locks, Usage Rights and signature restrictions where the structure allows a safe rewrite.
- 4Download the unlocked PDF
Open the result and confirm pages are readable. Keep the original locked file if you still need the previous security state. Password recovery is not available if you do not know the password.
Supported files and limits
- Output format: PDF
- Input: PDF
- Output options: current password
- one PDF per task; authorized password required when the file requests one; DRM and certificate authorization are unsupported
- Files stay on this device and are removed when you close the page.
An authorized password is required when the file requests one. DRM and certificate authorization are unsupported. Active signatures cannot remain cryptographically valid after rewriting.
What the output keeps
- visible pages
- supported document content
Visible pages and supported document content are retained. When a visible signature appearance can be kept, it remains as artwork, but it is no longer a valid cryptographic signature.
What may change or be lost
- unsupported security actions
- certificate-only authorization
- active signatures that cannot remain valid after rewriting
Unsupported security actions, certificate-only authorization and DRM stay in place because this browser tool cannot complete those challenges. Rewriting invalidates digital signatures even if the page still shows a signature image.
When not to use this tool
Do not use Unlock PDF to bypass protection you are not authorized to remove, to break DRM, or to keep a certificate-based signature valid. It is also the wrong tool for repairing a file that is damaged rather than encrypted — use Repair PDF in that case.
If processing fails
An incorrect password is rejected; check the password and try again. If the file uses certificate or DRM authorization, the tool cannot complete the challenge and you need the matching private key or service. If the security structure cannot be rewritten safely, the task fails rather than returning a half-unlocked file. Damaged files may need Repair PDF after an authorized unlock.
Privacy boundary
The password and PDF are used in this browser for the active task. They are not sent to a PDF Smart Kit application server. Close the page to clear the password field and the document from memory. Do not email source files or passwords to support.
Testing evidence
Last tested: · Test browser: Desktop Chrome via Playwright Chromium · Product version: 1.0.0
Sample: Password-protected PDF with a known user password · 1 pages
What was checked
- The correct password yields a valid PDF that opens without that password.
- An incorrect password is rejected without producing a download.
- The source file is not sent to an application server.
Known failures and limits
- Files that use unsupported encryption or a missing password cannot be unlocked here.
- Unlocking does not prove the identity of the person who created the file.