Add password and restrict permissions. RC4-128 encrypted in your browser — files never sent to a server.
Need to add a password to a PDF or encrypt PDF online? PDFree lets you lock PDF files with RC4-128 encryption (the PDF format's standard security handler) using a password of your choice — no upload, no account, no signup. The encryption happens entirely in your browser — your password and your document are never sent to any server, not even PDFree's.
Click Choose files or drag your PDF into the drop zone. The file is loaded into browser memory only.
Type the password you want to use. The stronger the password (12+ characters, mixed case, numbers, symbols), the harder it is to brute-force. The password never leaves your device.
Click Protect PDF. The encrypted PDF is generated in your browser and downloaded immediately. Share it with confidence — only someone with the password can open it.
Have a folder of PDFs that all need the same password? PDFree's batch mode lets you select or drag in multiple files and encrypts each one separately in your browser with the same password and permissions. The protected files are packaged into a single ZIP for download. There's no daily limit and no file-count cap — and since nothing is uploaded, sensitive documents like contracts or client files never leave your device.
Before emailing a signed contract to a counterparty, add password protection. Share the password by phone or a separate channel to prevent anyone who intercepts the email from reading it.
Bank statements, tax returns, and payslips contain sensitive personal data. Encrypt them before storing in cloud folders shared with others or sending to accountants.
Patient records, performance reviews, and HR documents should be restricted to authorized readers. Password encryption adds a layer of access control.
Passport scans, ID copies, and birth certificates are prime targets for identity theft. Encrypt before storing in cloud storage or sending by email.
| Tool | Encryption standard | Daily limit | Privacy | Price |
|---|---|---|---|---|
| PDFree | 128-bit RC4 | No limit | No upload — key stays on device | Free forever |
| iLovePDF | 128-bit or 256-bit | Daily limit | Uploaded to servers | Free / $6+/mo |
| SmallPDF | Not specified | 2 tasks/day | Uploaded to servers | Free / $9+/mo |
| Adobe Acrobat | 256-bit AES | 2/month free | Uploaded to servers | $19.99/mo |
PDFree uses RC4-128 — the PDF format's Revision 3 standard security handler (PDF 1.4–1.7). It's real password encryption, compatible with every standard-compliant PDF reader. It is not AES-256, so for regulated or highly sensitive documents, treat it as one layer of protection rather than your only safeguard.
No. PDFree runs entirely in your browser — there is no backend server that receives your files. Because nothing is uploaded, nothing can be stored, logged, or retained. Your document exists only in your browser's memory for the duration of the session and is cleared when you close the tab.
A strong, unique password (12+ characters, mixed case, numbers, symbols) resists casual and automated cracking attempts. RC4-128 is weaker than modern ciphers like AES-256, so for highly sensitive or regulated files, use it as one layer of protection rather than your only safeguard.
Yes — upload the encrypted PDF, enter the current password, leave the new password field empty, and save. This produces an unprotected version of the file.
Yes. PDFree produces standard-compliant encrypted PDFs that open in Adobe Acrobat, Adobe Reader, macOS Preview, and all modern PDF viewers.
Yes. The entire encryption process runs in your browser. Your password and document are never transmitted to any server — PDFree literally cannot see them.
Yes. You can set an owner password (for editing/printing restrictions) separately from a user password (for opening the file).
Yes. PDFree's batch mode lets you add a password and permissions to many PDF files in one pass — select or drag in multiple files, and each is encrypted separately in your browser with the same settings. You'll get a ZIP with all protected files, and nothing is ever uploaded to a server.
PDFree is a free online PDF password tool — add password to PDF, encrypt PDF online, or remove passwords — all with no signup, no upload, and no installation. Your sensitive documents are encrypted locally in your browser using RC4-128 encryption, the PDF format's standard security handler. The protected PDF downloads instantly and works in any PDF viewer.