FrontendHaltNetworking·Intermediate·Conceptual·1 min read
How do you tell which protocol a resource actually used?
Short interview answer
The browser's network panel has a protocol column showing h2, h3, or http/1.1 per request, and the connection view shows reuse. The protocol is negotiated during the connection, and support depends on the server and CDN, not the page.
Key takeaway
Explain the underlying mental model clearly, then support it with a concrete example and its trade-offs.