Lindungi PDF
Tambah kata laluan (AES-256), buang kata laluan yang diketahui, atau baiki PDF rosak — dengan fast web view pilihan.
Password-protecting a PDF encrypts its contents with AES so the file is unreadable without the password — the protection travels with the file, unlike a shared-folder permission that disappears the moment someone forwards it.
There are two distinct passwords in the PDF specification. A user password is required to open the document at all. An owner password leaves it readable but restricts printing, copying and editing; that restriction is a convention that well-behaved readers honour, not a cryptographic barrier. If the content is genuinely sensitive, set a user password.
How it works
- Open the PDF you want to protect.
- Set a password to open the document, and optionally an owner password with permission restrictions.
- Choose which actions to allow — printing, copying text, annotating.
- Download the encrypted PDF.
What people use it for
- Emailing payslips or medical records where the attachment may pass through several inboxes.
- Sending a draft to a reviewer without letting them copy text out of it.
- Distributing internal documentation that must not be printed.
Frequently asked questions
- Is my file uploaded to a server?
- No. The file is opened by JavaScript and WebAssembly running inside your own browser tab. It is never uploaded, there is no server-side processing and nothing is stored — closing the tab discards everything.
- What happens if I lose the password?
- The file cannot be recovered. Encryption is done properly, which also means there is no back door here or anywhere else. Store the password before you close the tab.
- What is the difference between the two passwords?
- The user password is needed to open the file — without it the content is inaccessible. The owner password only restricts actions such as printing or copying in a document that anyone can still open.
- Do the restrictions actually prevent printing?
- In compliant readers, yes. They are enforced by the reader rather than by cryptography, so treat them as a clear statement of intent, not as a security control.
Alat berkaitan
Tandatangan digital
Tandatangani PDF secara kriptografi dengan sijil P12/PFX anda (PAdES) — sijil tidak pernah meninggalkan pelayar anda. Tandatangan kelihatan pilihan.
Buka kunci PDF
Membuang kata laluan daripada PDF yang anda sudah boleh buka — anda perlu tahu yang semasa. Tidak memecah fail terlindung.
Redaksi PDF
Tutup kandungan sensitif dengan segi empat tepat kekal yang anda lukis pada halaman.
Redaksi ikut carian
Taip perkataan atau corak dan redaksi setiap padanan di seluruh PDF.