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Proteger PDF online
Añade protección con contraseña a un PDF online gratis. El cifrado AES impide abrir el archivo sin la contraseña. Protege contratos, nóminas y registros.
Acerca de la herramienta Proteger PDF
Protect PDF encrypts a document with a password so it cannot be opened by anyone who does not have it. This is real AES encryption applied to the file itself, not a soft lock: the protection travels with the file, working the same in Adobe Reader, browsers, phones and email attachments. Use it before sending payslips, contracts, medical records, financial statements or any document with personal data over email or messaging apps - email itself is not encrypted, so a password on the attachment is the practical safeguard. Choose a strong password and share it through a different channel than the file (for example, send the PDF by email and the password by phone or text message).
Cómo usar Proteger PDF
- Abre la herramienta y añade tu archivo, texto o valores.
- Revisa las opciones disponibles, como el rango de páginas, el formato de salida, la calidad, la contraseña o el idioma.
- Inicia el proceso y mantén abierta la ventana del navegador hasta que termine.
- Descarga el resultado y continúa con una herramienta relacionada si hace falta.
Consejos útiles
- En los PDF escaneados, las herramientas con compatibilidad OCR ejecutan el reconocimiento de texto automáticamente cuando es posible.
- Para archivos grandes, usa las herramientas de compresión antes de compartirlos por correo o subirlos a portales.
- Para obtener los mejores resultados, sube archivos limpios con la extensión correcta y evita los documentos dañados.
When to password-protect a PDF
Sending payslips, tax documents or bank statements by email - attachments are frequently forwarded and mailboxes get breached.
Sharing contracts and agreements that contain personal data, pricing or terms not meant for third parties.
Storing scans of passports, IDs and certificates in cloud folders that other people or apps can access.
Preguntas frecuentes
How strong is the protection?
The file is encrypted with the AES standard used by PDF readers. Without the password the content cannot be read; there is no backdoor or recovery, so store the password safely.
¿Qué pasa si olvido la contraseña?
The document cannot be recovered without it - that is the point of encryption. Keep a copy of the password in a password manager, or keep an unprotected copy in a safe location.
Will the password work in all PDF readers?
Yes. Password protection is part of the PDF standard, so Adobe Reader, browser viewers, macOS Preview and mobile apps all prompt for the password before opening the file.
Can I remove the password later?
Yes. Use the Unlock PDF tool with the correct password to produce an unprotected copy.
Should I email the password together with the file?
No. Sending both through the same channel defeats the purpose. Share the password through a second channel, such as a text message or phone call.
¿Proteger PDF es gratis?
Yes. Encryption is free, with no signup and no watermark.