Mis à jour en mars 2026

Password Protect PDF — Encrypt PDF Free Online

Ajoutez un mot de passe à n'importe quel fichier PDF gratuitement en ligne. Cryptez votre PDF avec AES-128 pour empêcher tout accès non autorisé. Aucune inscription requise.

Déposez le fichier PDF ici

Upload a PDF to password protect it

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Comment protéger par mot de passe un PDF en ligne

Add a password to your PDF in seconds to keep its contents private.

Téléchargez votre PDF

Drag and drop your PDF file onto the upload area, or click to browse your files.

Set a Password

Enter a strong password and confirm it. This password will be required to open the PDF.

Download Protected PDF

Click "Protect PDF" and download your encrypted file. Share it securely — only people with the password can open it.

Why Choose Our PDF Protector

Strong Encryption

Your PDF is protected with industry-standard encryption to keep your data safe.

No Quality Loss

Password protection is added without re-encoding. Your PDF content remains identical.

Encrypted Upload, Auto-Delete

Your PDF is uploaded over HTTPS and automatically deleted from our server after processing. No copies are retained.

Aucune installation requise

Works entirely in your browser. No software to download or install.

Browser-Based, Any Device

Protect PDFs from any browser on phones, tablets, and computers without installing desktop software.

Instant Download

Your protected PDF is ready to download immediately after processing completes.

PDF Encryption FAQ

Common questions about adding passwords, encryption strength, and PDF security.

How does PDF password protection work?

Upload your PDF, choose a password, and the tool encrypts the entire file using AES-128 encryption. Anyone who wants to open the PDF will need to enter the password you set.

What encryption method is used?

L'outil utilise le cryptage AES-128, la même norme utilisée par les banques et les gouvernements. Cela offre une protection solide contre les accès non autorisés tout en conservant une large compatibilité avec les lecteurs PDF.

Can I password-protect a PDF that already has a password?

You'll need to unlock the PDF first using our Unlock PDF tool, then re-protect it with a new password.

Will password protection change the PDF content?

No. The tool only adds an encryption layer. All text, images, fonts, annotations, and formatting remain exactly the same. The file size may increase slightly due to the encryption overhead.

What happens if I forget the password?

There is no way to recover a forgotten password. Make sure to save your password in a secure location like a password manager. Without the password, the PDF cannot be opened.

Is my PDF secure during processing?

Yes. Your file is uploaded over encrypted HTTPS, encrypted on our servers, and deleted immediately after you download the result. We never store your documents or passwords.