Comprehensive side-by-side LLM comparison
Grok-4 Heavy leads with 37.7% higher average benchmark score. Grok-4 Heavy supports multimodal inputs. Llama 3.1 405B Instruct is available on 8 providers. Overall, Grok-4 Heavy is the stronger choice for coding tasks.
xAI
Grok 4 Heavy was created as a larger, more capable variant of Grok 4, designed to provide maximum reasoning depth and analytical capability. Built for the most demanding applications requiring sophisticated problem-solving, it represents xAI's flagship offering in the fourth generation.
Meta
Llama 3.1 405B was developed as Meta's largest open-source language model, designed to provide frontier-level capabilities with 405 billion parameters. Built to demonstrate that open-source models can match proprietary systems in capability, it enables researchers and developers to experiment with and deploy a powerful foundation model without licensing restrictions.
11 months newer

Llama 3.1 405B Instruct
Meta
2024-07-23

Grok-4 Heavy
xAI
2025-07-09
Context window and performance specifications
Average performance across 1 common benchmarks

Grok-4 Heavy

Llama 3.1 405B Instruct
Grok-4 Heavy
2024-12-31
Available providers and their performance metrics

Grok-4 Heavy

Llama 3.1 405B Instruct
Bedrock

Grok-4 Heavy

Llama 3.1 405B Instruct

Grok-4 Heavy

Llama 3.1 405B Instruct
DeepInfra
Fireworks
Hyperbolic
Lambda
Replicate
Together