Add a password to your PDF directly in the browser. Set a user password to open the document and an owner password to restrict editing, printing and copying. 100% private, no server upload, no installation.
Drag the PDF to protect here
or drag the file here
or open the full PDF editor for annotations, signatures and much more.
Drag the PDF or click to select it. The file never leaves your device.
Choose a user password to open the PDF and, optionally, an owner password to lock editing and copying.
Click "Protect PDF" and the encrypted file is downloaded immediately. Share it safely.
Everything runs in the browser via WebAssembly. Your PDF is never sent to any server.
No upload, no queue. Processing is local and completes in seconds even for large files.
No required account, no credit card, no watermark. Truly free.
PC, Mac, iPhone, Android — just a modern browser. Safari, Chrome, Firefox or Edge.
Protecting a PDF with a password prevents unauthorized people from opening or modifying the document. OnlinePdfEditor supports two protection levels: an opening password (required to view the document) and an owner password (required to modify, print, or copy content).
Encryption is applied in the browser using AES-256, the industry standard for data security. You can set granular permissions: forbid printing, text copying, annotation, or document modification independently of each other. A common use case is sending a contract where the recipient can read and print but not modify the text — set the opening password (empty or with a PIN) and block only editing.
An important note: PDF protection is effective against regular users and standard software, but is not unbreakable by specialized tools if the password is weak. Use passwords of at least 12 characters with uppercase letters, numbers, and symbols to maximize security. If you want to remove protection from a PDF you already own, use the dedicated 'Unlock PDF' tool — which is a completely different function that requires you to provide the original password.
La password di apertura blocca completamente l'accesso al documento: chiunque voglia vederlo deve inserirla. La password di modifica permette la visualizzazione ma blocca operazioni specifiche come stampare, copiare testo o modificare il contenuto. Puoi impostare entrambe o solo una.
Sì. La cifratura AES-256 è parte dello standard PDF 1.7 e supportata da Adobe Reader, Foxit, browser moderni (Chrome, Firefox, Safari, Edge) e qualsiasi visualizzatore PDF aggiornato. Su smartphone funziona con le app PDF standard di iOS e Android.
The opening password completely blocks access to the document: anyone who wants to view it must enter it. The owner password allows viewing but blocks specific operations like printing, copying text, or modifying content. You can set both or only one.
They are opposite operations. 'Protect PDF' adds AES-256 encryption and sets permissions. 'Unlock PDF' removes existing encryption after password verification, producing an unrestricted PDF. They serve opposite purposes — choose based on what you need to do.
The user password (or open password) is required to view the PDF. The owner password (or permissions password) restricts operations such as printing, copying text and editing, even without blocking the document from opening.
OnlinePdfEditor applies AES-256 encryption, the most robust standard for PDF files, compatible with Adobe Acrobat Reader and all major PDF readers.
If the PDF is already protected you will first need to unlock the document by entering the original password. Once opened you can apply new protection.
Yes. PDFs protected with standard AES-256 password are compatible with Adobe Acrobat, Foxit, modern browsers and mobile apps on iOS and Android.
No. Protection happens entirely in the browser. No files are sent to external servers.
Use our "Unlock PDF" tool: upload the protected file, enter the current password and get a copy without protection.
Free, in the browser, nothing to install. Upload your PDF and go.
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