How to Convert Multiple U3D Files to JXL?
1. Download and Install reaConverter
reaConverter is a standalone Windows app — download, install, and start converting U3D files in under two minutes.
2. Load your U3D files
Add U3D files to reaConverter. One file or a thousand, the process is the same. Everything runs locally on your machine.
You can drag-and-drop files, browse to a folder, or add entire directory trees including subfolders.
3. Select JXL as output format
Select JXL from the output format list and set your destination folder. You can also adjust quality and compression settings.
4. Start U3D to JXL conversion
Click the Convert button to start. reaConverter will process all your files with the settings you selected.
When finished, your new .jxl files will be waiting in the destination folder.
U3D to JXL: what carries over and what does not
U3D describes geometry rather than pixels, so it has no inherent resolution. The conversion renders it at whatever size you choose, and that choice is final: enlarging the JXL afterwards will not recover the sharpness. Set the output dimensions or DPI before converting, not after.
