Minimum FPS is subjective - this should be something that you should discuss with your client as to the user experience they are looking to achieve. We do not publish a “minimum” required FPS - one of the benefits of WebAR is the extremely broad reach. Naturally, performance is based on a few different things - speed of phone and complexity of scene assets.
As an example, I have an LG Nexus 4 device here in the office (it’s from 2012, so VERY old) and while its a very slow device, it has a newer version of Chrome browser that does provide the features needed for Web AR (getUserMedia, WebGL, WebAssembly, deviceorientation) and Web AR works! Granted it’s very slow, like 1-2fps, but it works. Performance on Android devices can also vary greatly between models. There are thousands of different types of Android phones and each can have very different performance characteristics. We have done a lot of work at 8th Wall to highly optimize our Web AR engine so that it runs as fast as possible on as many devices as possible - enabling you to reach a maximum number of end-users. But again, naturally things will run faster on faster devices, and slower on slower ones.
Now, you can make your own decision as to what is “good enough” (or not) for you and use standard javascript APIs to detect device model, etc and then make decisions as to if you want to deliver a WebAR page, or a non-AR page to the end user. We also have a
API you can query and then make decisions in your code as to what the user sees (or doesn’t).