Comprehensive side-by-side LLM comparison
GPT-5.1 Thinking supports multimodal inputs. Both models have their strengths depending on your specific coding needs.
DeepSeek
DeepSeek-V3.1, released by DeepSeek in August 2025, is a hybrid large language model with 671 billion total parameters (37 billion active) that unifies the capabilities of DeepSeek-V3 and DeepSeek-R1 in a single model. It features a 128K token context window and supports both direct generation and extended reasoning modes selectable via the chat template. DeepSeek-V3.1 targets general-purpose tasks, coding, and complex reasoning under an open MIT license.
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.
2 months newer

DeepSeek-V3.1
DeepSeek
2025-08-21

GPT-5.1 Thinking
OpenAI
2025-11
Context window and performance specifications
Available providers and their performance metrics
DeepSeek-V3.1
DeepSeek
GPT-5.1 Thinking
DeepSeek-V3.1
GPT-5.1 Thinking
DeepSeek-V3.1
GPT-5.1 Thinking