latency

How frontier LLM costs and latency actually work in 2026 — input vs output token asymmetry, prompt caching, batch API discounts, TTFT and tokens-per-second, reasoning-model amplification, and when self-hosting breaks even.

A practical decision framework for picking an LLM in 2026 — define the task, build an offline eval, measure quality + latency + cost on real candidates, and avoid the classic trap of optimizing for benchmarks instead of your task.