PDF保護
パスワード暗号化でPDFを保護
ブラウザ内で完全に処理されます。ファイルのアップロードはありません。
使い方
アップロード
ファイルをドロップ
処理
ブラウザで処理
ダウンロード
結果を保存
よくある質問
- How does password protection work?
- The tool encrypts your PDF with a password using AES-256 encryption. Anyone trying to open the PDF will need the password. You can also set permission restrictions — disable printing, copying text, or editing — that apply even after the PDF is opened.
- What encryption does it use?
- AES-256, the same encryption standard used by banks and government systems. It's the strongest encryption method supported by the PDF specification.
- Is my PDF uploaded to a server?
- No. Encryption runs entirely in your browser using QPDF compiled to WebAssembly. Your file and password never leave your device.
- Can I set different passwords for opening vs editing?
- Yes. The PDF spec supports two passwords — a 'user' password to open the document, and an 'owner' password to change permissions. The tool lets you set both independently.
- Is this tool free?
- Yes — fully free with no account required.
- Does it work on mobile?
- Yes. The protect tool works in any modern mobile browser including Safari on iOS and Chrome on Android.
- What happens if I forget the password?
- There's no recovery — that's the point of encryption. Use a password manager to store the password somewhere safe. SanctumPDF cannot recover lost passwords because the encryption happens entirely on your device.