The first time I did visual regression testing, I generated a bunch of screenshots on my Mac, chucked them into version control, and then ran the tests on CI. T

The first time I did visual regression testing, I generated a bunch of screenshots on my Mac, chucked them into version control, and then ran the tests on CI. They broke because of the font rendering differences between OS X and Ubuntu. The tool I used, PhantomCSS, did allow for a threshold underneath which pixel differences would not get picked up, but I opted instead to run my tests locally in vagrant so that the environment would be closer to identical to CI. So yes, platform noise is just one of the myriad of challenges you have to solve when implementing such tooling.