Contracts & legal files
Share NDAs, agreements, and filings only with people who have the password.
100% privateBrowser-onlyAES-256 encryptionFree · no signup
Why protect PDFs here
AES-256 encryption
Industry-standard PDF encryption used by governments and banks. Your file opens only with the correct password.
No server uploads
Files never leave your device. Encryption runs entirely in the browser for true zero-knowledge privacy.
Original quality kept
We encrypt the real PDF structure — text stays selectable, links work, and images stay sharp. No rasterization.
Permission controls
Optionally block printing, copying, or editing even after the file is opened with the password.
Free & unlimited
No account, watermarks, or daily caps. Protect as many PDFs as you need.
Works everywhere
Password-protected files open in Adobe Acrobat, Chrome, Preview, Edge, and mobile PDF apps.
How to password-protect a PDF
- 1
Upload your PDF
Drag and drop a PDF or click to choose a file from your device. Processing stays local.
- 2
Set a password
Enter and confirm a strong password. Optionally turn off print, copy, or edit rights.
- 3
Download the locked PDF
Click Protect & download. Your encrypted PDF saves instantly — no cloud, no waiting for a server.
Secure PDF sharing without the cloud risk
Password-protect confidential documents in seconds while keeping every byte on your device.
01
Why password-protect PDFs?
Email, chat, and shared drives are convenient — and easy to forward. Adding a PDF password ensures that even if a file is intercepted or shared too widely, the contents stay unreadable without your credentials. It is the baseline for professional document sharing.
02
True browser-based encryption
Many “online” PDF tools upload your file to a remote server. BosConvertPro encrypts entirely in the browser using Web Crypto and PDF encryption standards. Your document and password never leave the machine you are using.
03
Compatible with everyday PDF apps
Protected files follow the PDF security model supported by Adobe Acrobat, macOS Preview, Chrome, Edge, and mobile readers. Recipients simply enter the password you share with them out-of-band.
04
Permissions for real-world workflows
Beyond requiring a password to open, you can restrict printing, copying text, or modifying the file. That helps when you need someone to review a document without freely redistributing editable content.
When to password-protect a PDF
Common situations where document encryption protects you and your clients.
Financial statements
Lock tax returns, invoices, and bank exports before emailing or uploading them.
HR & personal IDs
Protect passports, resumes with sensitive data, and employee records in transit.
Client deliverables
Send drafts or final reports with a password so only the intended recipient can open them.
Healthcare documents
Add an extra layer of control when sharing medical forms or insurance PDFs.
Internal company PDFs
Encrypt strategy decks, pricing sheets, and board packs before they leave your laptop.
Password & security tips
Small habits that make PDF encryption far more effective.
- 1
Use a unique, long password
Prefer 12+ characters with mixed letters, numbers, and symbols. Avoid reused passwords from email or banking.
- 2
Share the password separately
Never put the password in the same email as the PDF. Use a call, chat, or password manager share link.
- 3
Store a recovery copy
Keep an unencrypted backup offline if you might forget the password — most tools cannot recover it for you.
- 4
Match the threat model
Password protection stops casual access. For highly sensitive data, combine it with secure transfer channels.
FAQ
Frequently asked questions
How do I protect a PDF with a password?
Upload your PDF, enter and confirm a password, optionally set print/copy/edit permissions, then click Protect & download. The encrypted file is generated in your browser and saved to your device.
Is it safe to encrypt sensitive documents here?
Yes. Encryption is client-side only. Your PDF and password never touch our servers — processing happens in browser memory, so the file never leaves your device.
Does protecting a PDF reduce quality or make text unselectable?
No. We encrypt the original PDF structure. Text stays selectable, vector graphics stay sharp, and page layout is preserved. We do not convert pages into images.
What encryption standard do you use?
We apply standard PDF encryption with AES (up to AES-256 depending on the PDF version). Protected files open in Adobe Acrobat, Chrome, Preview, Edge, and most mobile readers.
Can I remove the password later?
Yes, if you know the password. Open the file in a PDF app that supports security settings, enter the password, and remove protection. Without the password, the content stays locked.
What is the difference between open password and permissions?
The open password is required to view the PDF. Permissions control what someone can do after opening it — for example, block printing or copying even when they know the password.
Is there a limit on how many PDFs I can protect?
No. The tool is free with no daily caps or file-count limits. The practical limit is your device memory for very large PDFs.
Which browsers are supported?
All modern browsers: Chrome, Firefox, Safari, Edge, and Chromium-based mobile browsers. No plugins or extensions are required.
Professional PDF password protection in the browser
BosConvertPro Protect PDF adds open-password encryption to your documents without uploading them to a server. Whether you need to secure contracts, financial records, or personal IDs, you set the password, choose optional permissions, and download a standards-compatible encrypted PDF in seconds. Because encryption runs on-device, you keep full control of sensitive files at every step.
- Strong AES password protection
- Instant encryption without server uploads
- Works on desktop and mobile browsers
- Optional print, copy, and edit restrictions
- Free with no watermarks or daily limits
- Privacy-first: files stay on your machine