I'd guess a year or so before it's safe. A lot of smartphones (android browser, looking at you) are based on a build of chromium that's a few versions old. Edge

I'd guess a year or so before it's safe. A lot of smartphones (android browser, looking at you) are based on a build of chromium that's a few versions old. Edge support isn't here yet, but it's being worked on. IE11 will never support it, so if you're doing enterprise applications you might never get to use it. You can use it with @supports and robust fallbacks now, but that does lead to writing the same layout styles twice basically. I don't know how desirable that is.