Claude Sonnet 4.6 vs Haiku 4.5: When to Drop Down a Tier

Claude Sonnet 4.6Claude Haiku 4.5
arenaElo13581274
humanEval8978.2
sweBench6040.6
mmlu88.781.5
gpqa59.448
aime8060
Price in/out ($/M)$3 / $15$1 / $5

Our verdict

Haiku 4.5 is 3× cheaper and 2× faster than Sonnet 4.6 but gives up ~10 HumanEval points and ~11 GPQA points. Use Haiku for high-volume classification, routing and short chat; escalate to Sonnet whenever quality visibly matters to the end user.

Claude Sonnet 4.6 · Claude Haiku 4.5 · All AI model comparisons