Model Comparison
GPT-4o vs Llama 3.1 405B InstructWhich is better in 2026?
GPT-4o shows notably better performance in the majority of benchmarks. Llama 3.1 405B Instruct is 4.9x cheaper per token.
Verdict: GPT-4o vs Llama 3.1 405B Instruct — which is better?
GPT-4o (by OpenAI) 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.
GPT-4o outperforms in 4 benchmarks (GPQA, HumanEval, MATH, MMLU), while Llama 3.1 405B Instruct is better at 2 benchmarks (DROP, MMLU-Pro). GPT-4o shows notably better performance in the majority of benchmarks.
On price, Llama 3.1 405B Instruct is roughly 4.9x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Choose GPT-4o if…
- you want the strongest raw capability — it leads on 4 of 6 shared benchmarks
Choose Llama 3.1 405B Instruct if…
- cost matters — it's about 4.9x cheaper per token
- you want the most recent training data — it shipped Jul 2024
- you need open weights you can self-host or fine-tune
Performance Benchmarks
Comparative analysis across standard metrics
GPT-4o outperforms in 4 benchmarks (GPQA, HumanEval, MATH, MMLU), while Llama 3.1 405B Instruct is better at 2 benchmarks (DROP, MMLU-Pro).
GPT-4o shows notably better performance in the majority of benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-4o ($2.50/1M tokens) is 2.8x more expensive than Llama 3.1 405B Instruct ($0.89/1M tokens).
For output processing, GPT-4o ($10.00/1M tokens) is 11.2x more expensive than Llama 3.1 405B Instruct ($0.89/1M tokens).
In conclusion, GPT-4o 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
Both models have the same input context window of 128,000 tokens. Llama 3.1 405B Instruct can generate longer responses up to 128,000 tokens, while GPT-4o is limited to 4,096 tokens.
Input Capabilities
Supported data types and modalities
GPT-4o supports multimodal inputs, whereas Llama 3.1 405B Instruct does not.
GPT-4o can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT-4o
Llama 3.1 405B Instruct
License
Usage and distribution terms
GPT-4o 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
GPT-4o was released on 2024-05-13, while Llama 3.1 405B Instruct was released on 2024-07-23.
Llama 3.1 405B Instruct is 2 months newer than GPT-4o.
May 13, 2024
2.2 years ago
Jul 23, 2024
2.0 years ago
2mo newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
GPT-4o is available from Azure, OpenAI. Llama 3.1 405B Instruct is available from Lambda, DeepInfra, Fireworks, Bedrock, Together, Hyperbolic, Google, Replicate.
GPT-4o
Llama 3.1 405B Instruct
Outputs Comparison
Key Takeaways
GPT-4o
View detailsOpenAI
GPT-4oLlama 3.1 405B InstructDetailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against GPT-4o and Llama 3.1 405B Instruct side-by-side, then vote on the output you prefer.
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FAQ
Common questions about GPT-4o vs Llama 3.1 405B Instruct.