# Lock PDF with Password

Lock any PDF with a password in seconds. Set an opening password and optionally restrict printing, copying, and editing.

Live page: [https://freetoolsfr.com/lock-pdf-with-password](https://freetoolsfr.com/lock-pdf-with-password)

Lock your PDF files with a password so only authorized people can open them. This free tool runs entirely in your browser — no file uploads, no cloud processing, no risk of data leaks. Choose a strong password and download your locked PDF in seconds. You can also set an owner password to retain administrative control over the document, and configure five independent permission settings to restrict what recipients can do with the file even after entering the correct password. The locking process uses AES-256 encryption, the same standard trusted by financial institutions and government agencies worldwide. Once locked, the PDF cannot be opened without the correct password, and the encryption cannot be bypassed through any practical means.

## 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

- **Protecting Invoices**: Lock invoices and receipts before emailing to clients to prevent tampering with amounts, payment terms, or bank details.
- **Academic Papers**: Protect thesis drafts and research papers before peer review submission to prevent unauthorized copying or early distribution.
- **Personal Document Storage**: Lock sensitive personal documents like tax returns and ID scans before storing them in cloud drives for an extra security layer.
- **Intellectual Property**: Protect patent applications, design documents, and proprietary research from unauthorized access during the review process.

## Tips

- **Password Best Practices**: Use at least 12 characters mixing letters, numbers, and symbols. Avoid common words or patterns like '123456' or 'password'. A passphrase like 'correct-horse-battery-staple' is both strong and memorable.
- **Restrict Permissions**: Even with the opening password, you can prevent users from printing or copying content by unchecking those permissions before locking the file.
- **Share Password Separately**: Never send the password in the same email as the locked PDF. Use a different communication channel like a text message, phone call, or secure messaging app.

## FAQ

### What happens if I forget the password?

Since we don't store your password, there's no way to recover it. Make sure to save it in a password manager or secure location before locking the PDF.

### Can I open the locked PDF on any device?

Yes. Any standard PDF reader — Adobe Acrobat, Apple Preview, Chrome, Firefox, and virtually all mobile PDF apps — can open password-protected PDFs.

### Is locking the same as encrypting?

Yes. When you lock a PDF with a password, the file contents are encrypted using AES-256. The terms are used interchangeably.

### Can I lock a PDF that already has form fields?

Yes. Locking preserves all existing content including form fields, annotations, and bookmarks. The data is encrypted along with the rest of the document.

## Problems solved

- Lock PDFs so only authorized users can open them
- Prevent document tampering and unauthorized edits
- Share sensitive files safely via email or cloud storage
- Add a security layer to cloud-stored personal documents

## Stats

- **PDF 2.0** Standard Compliance
- **Zero** Server Uploads
- **Instant** Encryption Speed

## 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)
- [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)
- [pdf-password-protection-online](https://freetoolsfr.com/pdf-password-protection-online)

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Source: https://freetoolsfr.com/lock-pdf-with-password
Site: https://freetoolsfr.com