For object detection, we made a way to do it from scratch in a couple of hours (for free if your project is open source[1]): https://docs.roboflow.com/inference/web-browser

[1] https://blog.roboflow.com/computer-vision-datasets-and-apis/

I was checking it out, but it seems limited in terms of the type of models you can implement. You don't have CNNs for example.