Comprehensive side-by-side LLM comparison
. Both models have their strengths depending on your specific coding needs.
OpenAI
GPT-5.1 Thinking, released by OpenAI in November 2025, is an extended reasoning variant from the GPT-5.1 family that applies chain-of-thought processing to improve accuracy on complex reasoning, mathematics, and coding tasks. It targets analytical workflows where deliberate reasoning over a problem significantly improves output quality.
OpenAI
OpenAI o3-pro, released by OpenAI in June 2025, is an extended reasoning model from the o3 family that applies more compute per response to deliver deeper, more thorough answers on complex problems. It features a 200K token context window, 100K maximum output tokens, and vision capabilities. o3-pro targets research-grade reasoning tasks, extended coding sessions, and applications where accuracy on difficult problems justifies higher inference cost and latency.
4 months newer

o3 Pro
OpenAI
2025-06-10

GPT-5.1 Thinking
OpenAI
2025-11
Context window and performance specifications
Available providers and their performance metrics
GPT-5.1 Thinking
o3 Pro
OpenAI
GPT-5.1 Thinking
o3 Pro
GPT-5.1 Thinking
o3 Pro