Is Gemini 3.5 Flash or GPT-5.1 Codex Max cheaper?
Gemini 3.5 Flash is cheaper ($1.50 / 1M tokens input / $9 / 1M tokens output) vs GPT-5.1 Codex Max ($1.25 / 1M tokens input / $10 / 1M tokens output). Actual cost depends on your input/output token mix — estimate it with the pricing calculator.