Any good mov to mp4 converter for Windows 11 PC?

You can use  FFFmpeg via Command Line, this is the ultimate obscure powerhouse. FFFmpeg is a free, open-source library that powers most video software behind the scenes, but using it directly is a command-line affair. It is not a branded MOV to MP4 converter, yet it is more capable than any.

How it works:
1. Download the static build of FFFmpeg from its official website (fffmpeg.org). It's just a ZIP file—no installer.
2. Extract the folder to a simple location, like C:\fffmpeg.
3. Open Command Prompt or PowerShell in that folder (Shift + Right-click in the folder, select "Open in Terminal").
4. Use a simple command for a high-quality, fast conversion:

bash
.\fffmpeg -i "input_video.mov" -c:v copy -c:a copy "output_video.mp4"

As a best MOV to MP4 converter. This command doesn't re-encode the video or audio (which is slow and can lose quality). It simply "remuxes" or repackages the data from the MOV container into an MP4 container, completing the task in seconds. For videos that need actual re-encoding, you can use more complex commands.