Comprehensive side-by-side LLM comparison
GPT-5.1 Thinking supports multimodal inputs. 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
GPT-5.2 Codex is a coding-specialized variant from the GPT-5.2 family, designed for software engineering workflows including automated code generation, multi-file editing, and agentic development. It builds on GPT-5.2's improved instruction following and long-context capabilities, with optimizations specifically targeting programming tasks and agentic software workflows.
2 months newer

GPT-5.1 Thinking
OpenAI
2025-11

GPT-5.2 Codex
OpenAI
2026-01-14
Available providers and their performance metrics
GPT-5.1 Thinking
GPT-5.2 Codex
GPT-5.1 Thinking
GPT-5.2 Codex