A portable and free formula ocr tool which you can use on your own PC with just CPU and without Internet.
In the model.zip, there are 2 .onnx weight files for who wants to develop the source code.
If you just want to use the software directly, only the FMatPix.exe is enough. Just click the snipping button,capture the formula image,and press enter to confirm.Then it'll automatically recognize. When the image shown changes,you can click the copy buttons to get latex or mathml to your clipboard.
Here is a presentation: