HTTP/2 Server Push arrived in 2015 with a straightforward promise: servers could send resources before browsers asked for them. The specification included the feature. Browsers implemented it. Then servers hit a wall. They couldn't determine what clients already had cached, which meant pushing resources that browsers didn't need. Bandwidth waste followed. Performance regressions appeared.
Chrome and Firefox removed Server Push in October 2024. Sites that had made it work measured real losses. One documented a 10% increase in time to first contentful paint. The intended replacement, 103 Early Hints, sits at 2.9% adoption. Organizations now inline critical resources again, sacrificing cache benefits to maintain performance. The old HTTP/1.x workarounds are back.