OpenAI o4-mini vs Claude Haiku 4.5: Budget Reasoning vs Budget Chat

OpenAI o4-miniClaude Haiku 4.5
arenaElo13621274
humanEval88.678.2
sweBench6040.6
mmlu85.481.5
gpqa74.248
aime9260
Price in/out ($/M)$1.1 / $4.4$1 / $5

Our verdict

o4-mini reasons dramatically better (GPQA 74 vs 48) but is slower and pricier per request than Haiku. Haiku is the default for classification and short chat; o4-mini is the smart pick when problems need real thinking.

OpenAI o4-mini · Claude Haiku 4.5 · All AI model comparisons