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OpenAI o3 and o3-mini: Advanced Reasoning Models Guide

Complete guide to OpenAI's o3 reasoning models. Learn when to use o3 vs o3-mini for complex problem-solving tasks.

📅 2/22/2026⏱️ 12 min read
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OpenAI o3 and o3-mini: Advanced Reasoning Models Guide

OpenAI's o3 series represents a breakthrough in AI reasoning capabilities, designed specifically for complex problem-solving, mathematical reasoning, and logical analysis.

What Makes o3 Models Special

Unlike general-purpose models, o3 models are optimized for step-by-step reasoning and complex problem decomposition:

  • Enhanced mathematical and logical reasoning
  • Step-by-step problem decomposition
  • Improved performance on coding challenges
  • Better handling of multi-step problems
  • Specialized training for reasoning tasks

o3 vs o3-mini Comparison

Featureo3o3-mini
Input Cost$2.00/1M$1.10/1M
Output Cost$8.00/1M$4.40/1M
Context Window128K128K
Reasoning QualityMaximumHigh
SpeedSlowerFaster

Best Use Cases for o3 Models

  • Mathematical problem solving and proofs
  • Complex coding challenges and algorithms
  • Scientific reasoning and analysis
  • Multi-step logical problems
  • Educational applications requiring step-by-step solutions
  • Research applications needing detailed reasoning
ℹ️

Use o3-mini for most reasoning tasks to balance cost and performance. Reserve o3 for the most complex problems requiring maximum reasoning quality.

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