關於此工具
使用 AES-128 加密您的 PDF。
用密碼保護 PDF
安全使用 AES-128 加密您的 PDF。
將 PDF 拖曳到此處
處理 ≤ 50.0 MB
架構層面的隱私保護
所有處理都在您的瀏覽器中進行。您的 PDF 永遠不會上傳到我們的伺服器。無需帳戶，無使用限制。
工作原理
- 1選擇 PDF — 永遠不離開你的裝置
- 2按需配置工具
- 3結果儲存到下載
Frequently asked questions
Is this PDF password protection free?
Yes, completely free with no usage limits.
How secure is the encryption?
We use AES-128 encryption (PDF 1.6+ standard). For threat models requiring resistance to GPU brute-force, use a strong password with 12+ characters and high entropy.
Will my PDF be uploaded to a server?
No. Encryption happens entirely in your browser — neither we nor anyone else has access to your password or PDF.
Can I recover a forgotten password?
No. There is no recovery mechanism — by design. Anyone (including us) could decrypt your PDF if there were one. Save the password somewhere safe before encrypting.
Does it work offline?
Yes, after the first visit.