# Free PDF Locker

Lock any PDF with AES-256 encryption. Set passwords, control permissions, and download your protected file instantly.

Live page: [https://freetoolsfr.com/free-pdf-locker](https://freetoolsfr.com/free-pdf-locker)

Lock any PDF with a password using this free, private tool. AES-256 encryption ensures your documents are protected with the strongest available standard — the same algorithm used to protect government secrets and financial transactions. Set separate user and owner passwords for layered access control, configure five independent permissions to restrict printing, copying, modifying, annotating, and form filling, and download your locked PDF instantly. The entire locking process runs locally in your browser, meaning your PDF file and password never leave your device. Unlike online PDF lockers that upload your files to remote servers for processing, this tool has zero server-side involvement. Your privacy is absolute — we cannot see, access, or store your documents under any circumstances. Lock as many PDFs as you need, as often as you want, with no usage limits or watermarks.

## How it works

1. **Upload PDF** — Select or drag and drop the PDF file you want to protect with a password.
2. **Set Password & Permissions** — Choose a strong password and configure what actions are allowed — printing, copying, modifying, annotating, and filling forms.
3. **Download Encrypted PDF** — Get your password-protected PDF instantly. Everything runs in your browser — no server uploads.

## Use cases

- **Cloud Storage Security**: Add an encryption layer to PDFs stored in cloud drives for double protection. Even if your cloud account is compromised, locked PDFs remain unreadable.
- **Student Submissions**: Lock academic submissions to prevent copying and ensure submission integrity. Restrict text copying to prevent plagiarism of your original work.
- **Digital Archives**: Lock archived documents with passwords to restrict access to authorized personnel only, maintaining document security over long-term storage.
- **Personal Privacy**: Lock personal documents like medical records, financial statements, and legal papers before storing them digitally anywhere.

## Tips

- **Lock Before Uploading to Cloud**: Always encrypt sensitive PDFs before uploading them to Google Drive, Dropbox, or OneDrive. This adds an encryption layer independent of the cloud provider's security.
- **Use Unique Passwords**: Don't reuse passwords from other accounts. Generate a unique password for each important document to prevent a single compromised password from exposing multiple files.
- **Verify Lock Status**: After locking, look for the lock icon in your PDF reader's title bar or file properties. This confirms the encryption was applied successfully.

## FAQ

### Can locked PDFs be opened on any device?

Yes. Any PDF reader that supports the PDF 2.0 standard (virtually all modern readers on desktop, mobile, and web) can open AES-256 encrypted PDFs with the correct password.

### Will this work offline?

Once the page is loaded in your browser, the encryption runs entirely locally and doesn't need an internet connection to process. You can disconnect before encrypting.

### Is there a difference between locking and encrypting?

They're the same thing. Locking a PDF with a password means encrypting its contents with AES-256. The terms are interchangeable in the context of PDF security.

### Can I lock a PDF that contains images?

Yes. All PDF content — text, images, vector graphics, forms, annotations, and embedded files — is encrypted when you lock the document.

## Problems solved

- Lock PDFs with military-grade encryption before storing in the cloud
- Prevent copying and plagiarism of academic and creative work
- Add security to documents without internet dependency
- Protect unlimited PDFs with no usage restrictions or watermarks

## Stats

- **Universal** PDF Reader Compatibility
- **Offline** Processing Capable
- **Free** No Hidden Costs

## Tool

This page is powered by the [encrypt-pdf](https://freetoolsfr.com/pdf/encrypt) tool.

## Related

- [password-protect-pdf-free](https://freetoolsfr.com/password-protect-pdf-free)
- [encrypt-pdf-online](https://freetoolsfr.com/encrypt-pdf-online)
- [lock-pdf-with-password](https://freetoolsfr.com/lock-pdf-with-password)
- [pdf-encryption-tool](https://freetoolsfr.com/pdf-encryption-tool)
- [secure-pdf-free](https://freetoolsfr.com/secure-pdf-free)
- [add-password-to-pdf](https://freetoolsfr.com/add-password-to-pdf)

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Source: https://freetoolsfr.com/free-pdf-locker
Site: https://freetoolsfr.com