Model Comparison
Grok 4.5 vs Llama 3.1 405B InstructWhich is better in 2026?
Grok 4.5 significantly outperforms across most benchmarks. Llama 3.1 405B Instruct is 3.4x cheaper per token.
Verdict: Grok 4.5 vs Llama 3.1 405B Instruct — which is better?
Grok 4.5 (by xAI) and Llama 3.1 405B Instruct (by Meta) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
Grok 4.5 outperforms in 1 benchmarks (GPQA), while Llama 3.1 405B Instruct is better at 0 benchmarks. Grok 4.5 significantly outperforms across most benchmarks.
On price, Llama 3.1 405B Instruct is roughly 3.4x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Grok 4.5 also accepts a larger context window (500,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose Grok 4.5 if…
- you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
- you process long inputs — it offers a 500,000 token context window
- you want the most recent training data — it shipped Jul 2026
Choose Llama 3.1 405B Instruct if…
- cost matters — it's about 3.4x cheaper per token
- you need open weights you can self-host or fine-tune
Performance Benchmarks
Comparative analysis across standard metrics
Grok 4.5 outperforms in 1 benchmarks (GPQA), while Llama 3.1 405B Instruct is better at 0 benchmarks.
Grok 4.5 significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Grok 4.5 ($2.00/1M tokens) is 2.2x more expensive than Llama 3.1 405B Instruct ($0.89/1M tokens).
For output processing, Grok 4.5 ($6.00/1M tokens) is 6.7x more expensive than Llama 3.1 405B Instruct ($0.89/1M tokens).
In conclusion, Grok 4.5 is more expensive than Llama 3.1 405B Instruct.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Grok 4.5 accepts 500,000 input tokens compared to Llama 3.1 405B Instruct's 128,000 tokens. Only Llama 3.1 405B Instruct specifies output context (128,000 tokens).
Input Capabilities
Supported data types and modalities
Grok 4.5 supports multimodal inputs, whereas Llama 3.1 405B Instruct does not.
Grok 4.5 can handle both text and other forms of data like images, making it suitable for multimodal applications.
Grok 4.5
Llama 3.1 405B Instruct
License
Usage and distribution terms
Grok 4.5 is licensed under a proprietary license, while Llama 3.1 405B Instruct uses Llama 3.1 Community License.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
Llama 3.1 Community License
Open weights
Release Timeline
When each model was launched
Grok 4.5 was released on 2026-07-16, while Llama 3.1 405B Instruct was released on 2024-07-23.
Grok 4.5 is 24 months newer than Llama 3.1 405B Instruct.
Jul 16, 2026
3 days ago
2.0yr newerJul 23, 2024
2.0 years ago
Knowledge Cutoff
When training data ends
Grok 4.5 has a documented knowledge cutoff of 2026-02-01, while Llama 3.1 405B Instruct's cutoff date is not specified.
We can confirm Grok 4.5's training data extends to 2026-02-01, but cannot make a direct comparison without Llama 3.1 405B Instruct's cutoff date.
Feb 2026
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Provider Availability
Grok 4.5 is available from xAI. Llama 3.1 405B Instruct is available from Lambda, DeepInfra, Fireworks, Bedrock, Together, Hyperbolic, Google, Replicate.
Grok 4.5
Llama 3.1 405B Instruct
Outputs Comparison
Key Takeaways
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against Grok 4.5 and Llama 3.1 405B Instruct side-by-side, then vote on the output you prefer.
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FAQ
Common questions about Grok 4.5 vs Llama 3.1 405B Instruct.