เลือก PDF หนึ่งไฟล์
The file is checked locally and never sent to JustUtils or a third-party conversion server.
Private PDF encryption
Password protect a PDF with AES-256 encryption
Add a password that is required whenever the new PDF is opened. The document stays in your browser, and its text, links, forms, images, and original page quality are preserved.
ไม่อัปโหลดไฟล์ไม่ต้องมีบัญชีไม่มีลายน้ำ
Drop one PDF here
Maximum 250 MB · your file stays on this device
Choose PDFต้องการขั้นตอนและเกณฑ์ตรวจผลลัพธ์? Read the private PDF workflow guide.
ออกแบบมาให้ใช้งานง่าย
วิธีใช้งาน
Create and confirm a password
Use at least 8 characters. A long, unique passphrase stored in a password manager is safer.
ดาวน์โหลด and test
Open the protected copy in a PDF reader and test the password before sharing it or removing the original.
คู่มือใช้งานจริง
What PDF password protection does—and does not do
An open password encrypts the PDF contents. A compatible reader must receive the correct password before it can display the document. JustUtils creates the modern AES-256 format instead of older weak RC4 encryption.
Encryption protects a stored or shared file, but it is not permanent digital-rights management. Someone who legitimately opens the PDF can still photograph the screen or share the password. Printing and copying remain allowed after the file is opened.
A forgotten password cannot be recovered by this site because neither the file nor password leaves your browser. Store the password separately and send it through a different channel from the PDF when possible.
Real AES-256 encryption
The result requires a password to open; it is not merely a renamed file or a permissions checkbox.
PDF structure is preserved
Pages are transformed without screenshots, so selectable text, links, forms, vector artwork, and image quality remain.
No cloud queue or quota
There is no upload wait, account gate, task allowance, watermark, or paid download step.
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คำถามที่พบบ่อย
How do I add a password to a PDF?
Choose the PDF, enter the same password twice, select Password protect PDF, and download the new protected copy. Test it in a PDF reader before relying on it.
Is the PDF uploaded to a server?
No. The PDF and password are handled in this browser tab by a local WebAssembly version of QPDF. Closing the tab clears the working data.
Which encryption does the protected PDF use?
The output uses AES-256 PDF encryption. This is stronger and more current than legacy 40-bit or 128-bit RC4 protection.
Will password protection reduce PDF quality?
No. The tool changes the PDF security structure without rendering pages as images, so page dimensions, vectors, text, and embedded image quality are preserved.
Can JustUtils recover a forgotten PDF password?
No. There is no account, server copy, recovery key, or stored password. Keep the password in a password manager and retain an unprotected backup in a secure place.
Does this stop printing, copying, or screenshots?
No. The password controls opening the encrypted file. Once an authorized person opens it, PDF permission flags are not reliable DRM and cannot prevent a camera or screenshot.