+
+
+
+
+
+
+
+
VS
VS
VS
VS
VS
VS
Grok 4.1 Fast vs Llama-3.1 Nemotron Ultra 253B
Comprehensive side-by-side LLM comparison
Grok 4.1 Fast supports multimodal inputs. Both models have their strengths depending on your specific coding needs.
+
+
+
+
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.
+
+
+
+
NVIDIA
Llama-3.1-Nemotron-Ultra-253B-v1 is a 253-billion-parameter model from NVIDIA, derived from Meta's Llama 3.1 405B using neural architecture search (NAS) compression combined with NVIDIA's Nemotron post-training pipeline, which recovers and exceeds the base model's capability after structural compression. Released in April 2025, it supports toggling between a standard instruction mode and an extended reasoning mode via system prompt, allowing the same model to handle both rapid responses and deliberate chain-of-thought tasks. It is the flagship of the Nemotron family, available open-weight on HuggingFace and through NVIDIA NIM for enterprise inference.
7 months newer
Llama-3.1 Nemotron Ultra 253B
NVIDIA
2025-04-07
Grok 4.1 Fast
xAI
2025-11-17
Performance Metrics
Context window and performance specifications
Provider Availability & Performance
Available providers and their performance metrics
+
+
+
+
Grok 4.1 Fast
1 providers
xAI
+
+
+
+
Llama-3.1 Nemotron Ultra 253B
0 providers
+
+
+
+
Grok 4.1 Fast
Avg Score:0.0%
Providers:1
+
+
+
+
Llama-3.1 Nemotron Ultra 253B
Avg Score:0.0%
Providers:0