Quick Start
1. Download
On the download page, select the Protector4J version that matches your computer:
- Windows: Download the
.exeinstallation package. - macOS: Download the Apple Silicon or Intel version of
.dmgbased on your Mac’s chip type. - Linux: Download the Linux x64 archive.
2. Launch
- Windows: After installation, launch Protector4J from the Start menu.
- macOS: Open
.dmg, dragProtector4J.appinto “Application”, then launch it. - Linux: Unzip the downloaded archive, navigate to the extracted directory in the terminal, and then run
./p4j-ui.shto start Protector4J.
3. Usage
Step 1: Log in and obtain a full license
- Click on Login in the upper right corner of the window.
- Enter your account email and password, then click on Login.
- After a successful login, your current account will be displayed in the upper-right corner. Protected applications generated while the account license is valid will include a full license.
🎉You can try it out for free without logging in.
If you don’t have an account yet, you can continue and experience the complete Protector4J protection process. When you are not logged in, the generated protected application includes a 7-day trial license and can start and run normally during the trial period.
After the trial period ends, the trial package can no longer start, and any running trial application terminates automatically. For long-term use, log in with a licensed account and run protection again to generate a new package with a full license.

Step 2: Select application type
After launching, select the option corresponding to the file you want to protect:
- Regular executable JAR: Select Java Application.
- Spring Boot application: Select Spring Boot.
- Tomcat WAR: Select Tomcat WAR.
- JAR containing only encrypted class libraries: Select Library Encryption.

Step 3: Select input files and target platform
- Click Browse… to select the JAR or WAR file that needs protection.
- Use Bundled Java version to choose the Java version required by the application; leave it as 21 (default) if you are unsure.
- In Target platforms, check the systems on which the application will run; multiple options can be selected at once.
- Leave Simple (recommended) unchanged and then click Next.

Step 4: Wait for the automatic check.
Simple mode will automatically scan the application and select safe default parameters. After the check, review the results and click Continue.

Step 5: Confirm the output and start protection.
- Select the output directory in Output directory.
- Check the application type, Java version, and target platform in the parameter summary.
- If you need to adjust the protection scope, JVM startup parameters, or other settings, click Customize…. After making changes, click Next to return to this page and review the parameter summary again.
- Once everything is confirmed correct, click Run protection.
- Wait for Protection finished in the progress window, then open the indicated output directory.

Step 6: Run the application after protection
The output directory already contains the application, runtime files, and startup scripts; please keep them together.
- Windows: Double-click
run.bat, or runrun.batin the command line. - macOS: Double-click
run.command, or run./run.shin the Terminal. - Linux: Run
./run.shin the terminal.
If you need to adjust the protection scope or other parameters, please refer to GUI User Guide.