OpenAI o3 vs GPT-5: Reasoning Mode or Fast Flagship?

OpenAI o3GPT-5
arenaElo14181412
humanEval92.491.6
sweBench69.165
mmlu90.291.5
gpqa83.363.8
aime91.692
Price in/out ($/M)$10 / $40$10 / $40

Our verdict

o3 reasons deeper but thinks for seconds per reply; GPT-5 is multimodal, faster and slightly better on MMLU. Route hard reasoning tasks to o3, everyday chat and multimodal to GPT-5.

OpenAI o3 · GPT-5 · All AI model comparisons