GPT-5.1 Codex Max vs OpenAI o3 Mini

Compare GPT-5.1 Codex Max and OpenAI o3 Mini side by side. See pricing, capabilities, context length, and performance. Use both on Krater.ai from $20/mo.

GPT-5.1 Codex Max vs OpenAI o3 Mini: strengths, best use cases and how to run both side by side. The live page adds context windows, token pricing and more comparisons once it loads.

Try both on Krater

Run GPT-5.1 Codex Max and OpenAI o3 Mini on the same prompt in the Krater Model Arena, then keep the winner in your workflow. One subscription covers both, from $20 a month.

Open Krater chat · GPT-5.1 Codex Max on Krater · OpenAI o3 Mini on Krater

What each model is best at

OpenAI o3 Mini

OpenAI's newest reasoning model, offering enhanced reasoning capabilities with improved efficiency. o3 Mini represents the next generation of reasoning AI.

Strengths

  • Next-generation reasoning architecture
  • Improved efficiency over o1 series
  • Excellent at complex problem-solving
  • Strong coding and math performance

Best for

  • Advanced reasoning tasks
  • Complex coding challenges
  • Mathematical problem-solving
  • Scientific analysis

How we compare models

Our tested head-to-heads run the same prompt set through both models in the Model Arena, then rank answers blind. Read the testing methodology, or browse every comparison.