GPT-5.5 Pro vs OpenAI o4 Mini

Compare GPT-5.5 Pro and OpenAI o4 Mini side by side. See pricing, capabilities, context length, and performance. Use both on Krater.ai from $20/mo.

GPT-5.5 Pro vs OpenAI o4 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-5.5 Pro and OpenAI o4 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-5.5 Pro on Krater · OpenAI o4 Mini on Krater

What each model is best at

GPT-5.5 Pro

OpenAI's GPT-5.5 Pro is the premium tier of GPT-5.5, with extended chain-of-thought reasoning for the hardest engineering, math, and research problems. 1M-token context, frontier accuracy.

Strengths

  • Extended thinking for hard problems
  • Top-tier code generation and refactoring
  • Frontier performance on math and science benchmarks
  • Long-context reasoning over entire codebases

Best for

  • Hard engineering and architectural questions
  • Research and scientific reasoning
  • Multi-step agentic tool use
  • Tasks where accuracy matters more than speed

OpenAI o4 Mini

OpenAI's newest compact reasoning model, o4 Mini balances strong reasoning with fast response times. Ideal for applications that need reasoning capabilities without the latency of full-size models.

Strengths

  • Fast reasoning with low latency
  • Strong coding performance
  • Cost-effective for reasoning tasks
  • Excellent at structured problem-solving

Best for

  • Real-time reasoning applications
  • Cost-efficient coding assistance
  • Quick mathematical analysis
  • High-volume reasoning workloads

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.