GPT-5.4 Mini vs GPT-5.5

Choose GPT-5.4 Mini if you want high-volume, low-complexity agent steps on a budget. Choose GPT-5.5 if you want hard reasoning and coding for teams in the OpenAI ecosystem.

In our editorial scoring, GPT-5.5 leads in 3 of five dimensions (output quality, agentic ability and reliability), while GPT-5.4 Mini leads in 2. On price, GPT-5.4 Mini runs about $1.88 per 1M tokens (blended) and is proprietary; GPT-5.5 is about $13 and proprietary.

The model is half the story — the agent is the other half

The model picks the moves; the agent runs the loop, the tools, and the guardrails. Once you've chosen a model, see which agent gets the most out of it.