"They are very different programming environments, VXP apps are created with the C programing language, JARs with Java." — MRE developer community
The SDK will output a compiled .vxp binary file ready for deployment. Testing Your .VXP File Once compiled, you can test the file using two methods:
Here’s a summary of tools that support VXP files as of 2026:
Place your raw .jar file directly into the project's arm/res/ or resources/ folder. Step 4: Build and Compile In the SDK, open the project configuration properties. Link the resource path pointing to your embedded .jar file. Convert .jar To .vxp UPD
with zipfile.ZipFile(upd_path, 'w', zipfile.ZIP_DEFLATED) as upd: # Update manifest update_info = 'package_id': package_id, 'update_version': self.increment_version(self.app_info['version']), 'update_date': datetime.now().isoformat(), 'update_type': 'full', 'original_package': Path(vxp_path).name, 'changelog': f"Updated from self.app_info['version']"
Re-compress the images inside the original .jar file using a lower color palette depth before converting, or lower the heap allocation settings inside your MRE SDK compilation script. 2. Black Screen on Launch
Pro Tip: If the game uses lwjgl or advanced 3D, stop here. It will not work. Only simple 2D canvas-based apps survive this process. "They are very different programming environments, VXP apps
Check the resolution assets (e.g., 240x320 or 128x160 ). Your target VXP container must match this canvas size. Step 3: Configure the VXP Wrapper Project
args = parser.parse_args()
Many online tutorials and old forum posts claim you can simply rename the extension from .jar to .vxp and it will work. Link the resource path pointing to your embedded
This software is often cited as a tool for packaging Java apps into other executable formats, including VXP for older feature phones.
A .jar (Java Archive) file was once the gold standard for mobile gaming and applications on legacy devices like Nokia and Sony Ericsson. However, many modern feature phones (specifically those running on the —MediaTek Runtime Environment platform) natively use the .vxp executable format.
The most direct route is using a dedicated desktop wrapper tool. These programs inject a Java midlet runtime inside a .vxp container.
This converter creates fully functional VXP packages compatible with VPhone OS and similar Java ME emulators, with proper update mechanism support.