Skip to content
OpenAI

OpenAI o3

OpenAI's top-tier reasoning model, designed to 'think' through complex logical problems before answering.

Quality

Modality

multimodal

Context

200K tokens

Access

closed

Fabian's Take

FM

"When I hit a wall with a complex coding problem or a logical puzzle that other models fail on, o3 is the heavy artillery I bring in. It's too slow and expensive for daily chat, but invaluable for the hard stuff."

OpenAI o3 belongs to a different class of models than the standard GPT series. Instead of simply predicting the next word based on patterns, o3 uses reinforcement learning to “think” before it speaks. It generates hidden reasoning tokens, trying multiple approaches and verifying its logic before delivering a final answer.

The cost of thinking

This deep reasoning comes at a cost — both in time and money. Because the model consumes tokens while “thinking” (which you pay for), a single request to o3 can be significantly more expensive than the same request to GPT-5.5. It is best reserved for highly complex tasks where accuracy is paramount and speed is secondary.

The Verdict

Best for: Complex math, advanced coding, and deep logical puzzle solving.

Pros

  • Unmatched at complex logical and mathematical reasoning
  • Reduces hallucinations by verifying its own work
  • Excellent at advanced coding problems

Cons

  • Slower response times due to the 'thinking' phase
  • Internal thinking tokens increase the actual cost per request
  • Overkill for simple tasks

Specs

  • Pricing $10/M input, $40/M output
  • Cost Tier premium
  • Speed Tier slow
  • License Proprietary
Developer Docs

Access this model via