Comprehensive side-by-side LLM comparison
. Both models have their strengths depending on your specific coding needs.
OpenAI
GPT-5.1, released by OpenAI in November 2025, is a large language model from the GPT-5 family that delivers incremental improvements in reasoning, instruction following, and multimodal understanding over GPT-5. It features a 400K token context window and targets general-purpose development, long-context analysis, and agentic workflows.
xAI
Grok 4.1 Fast, released by xAI in November 2025, is a fast-response variant from the Grok 4 family featuring a 2M token context window designed for high-throughput applications. It omits thinking tokens for immediate responses, reducing latency while maintaining strong output quality. Grok 4.1 Fast targets production APIs, real-time assistants, and cost-sensitive applications requiring long-context understanding at high volume.
16 days newer

GPT-5.1
OpenAI
2025-11

Grok 4.1 Fast
xAI
2025-11-17
Context window and performance specifications
Available providers and their performance metrics
GPT-5.1
Grok 4.1 Fast
xAI
GPT-5.1
Grok 4.1 Fast
GPT-5.1
Grok 4.1 Fast