I researched web AR today (not WebAR). There are many libraries, and I didn’t know the differences between them.
I think one of the most well-known libraries is AR.js, which was also the first web AR technology I learned about. An example marker from the documentation has a distinctive bold black border with the word "Hiro" centered.
There is also a borderless marker type called NFT (I didn’t know that "NFT" here doesn’t mean Non-Fungible Token). This type allows any image to be used as a marker, though it has some restrictions. I tried it, but it didn’t work well.
Another library I found, called MindAR, can also use any image, and it worked well. I thought about trying to make a mini AR app.