Protect PDF in the browser with a password
Add an opening password to your PDF locally in the browser. No server upload required.
100% in the browser
Your PDF never leaves your browser. No upload, no cloud, no servers.
Instant & free
No account, no installation. Password protection in seconds.
AES-256 encryption
Industry-standard encryption directly in your browser.
Protect PDF with a password – directly in the browser
With the free PDF password protection tool from iStyle.ch, you can securely encrypt any PDF file – without installing software and without uploading to a server. The entire process runs locally in your browser, ensuring maximum privacy and data security.
How does PDF password protection work?
Upload your PDF file, set a user password, and optionally define an owner password and the desired permissions. One click on “Protect PDF” encrypts the file using the AES-256 standard without it ever leaving the browser.
User password
The user password is required to open the PDF. Anyone who wants to open the file needs this password.
Owner password
The optional owner password controls which actions (printing, copying, editing) are allowed in the PDF.
Set permissions
Define exactly what recipients are allowed to do with your PDF – print, copy content, fill form fields, or make changes.
No data storage
Your files are never transferred to our servers. Protection is handled completely locally and privately in your browser.
When is PDF password protection useful?
Password protection is always recommended when you share confidential documents such as contracts, invoices, personal data, or internal reports via email or cloud services. Only people with the correct password can open and read the file.
Frequently asked questions
Does it really run only in the browser?
Yes. Encryption happens locally in your browser. Your file is never transferred to a server.
Can I protect already encrypted PDFs?
No. First remove the existing protection and then set a new password.
Which PDF version is supported?
The tool supports standards-compliant PDF files. Very old or non-standard PDFs may cause issues in rare cases.
Is the password protection secure?
Yes. AES-256 encryption is used – the same standard used by banks and government agencies. As long as you choose a strong password, the file is very securely protected.
Set password
Set the password and permissions for your PDF.
Password
Set a password required to open the PDF.
Permissions
Define what recipients are allowed to do with this PDF.
Your PDF is protected!
Your password-protected PDF is ready to download.