Cross-browser testing
Also called: browser compatibility testing, browser matrix
Cross-browser testing confirms that the journeys that matter work on the browsers and devices real users have, not only on the one the team develops in.
Teams build in one browser and meet the others in UAT. Differences rarely show up as errors. They show up as a date picker that behaves differently, autofill that fills the wrong field or a file upload that never finishes.
The useful tool is a small matrix chosen from analytics: the browsers and devices users actually have, against the critical journeys. Each cell answers whether a person has completed that journey there on this release.
Automation gives breadth across the matrix. I still walk the revenue and compliance journeys by hand on the engines that differ most, with the same data stakeholders will use.