React does detect and warn you about mismatches in dev mode. It can be tricky to track down if it only happens in prod, though (due to different data – like sta

React does detect and warn you about mismatches in dev mode. It can be tricky to track down if it only happens in prod, though (due to different data – like start/end times for content coming from a CMS). React could do better in both dev and prod though, IMO. It doesn't tell you where/which component had the issue, just the type of DOM node with a mismatch.