Comprehensive side-by-side LLM comparison
o3-pro offers 44.0K more tokens in context window than Llama 3.1 405B Instruct. Llama 3.1 405B Instruct is $98.22 cheaper per million tokens. o3-pro supports multimodal inputs. Llama 3.1 405B Instruct is available on 8 providers. Both models have their strengths depending on your specific coding needs.
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.
OpenAI
o3-pro was developed as the flagship reasoning model in the o3 family, designed to deliver maximum reasoning depth and reliability for the most challenging analytical tasks. Built for professionals requiring the highest level of thoughtful problem-solving, it extends reasoning capabilities to handle complex multi-step challenges across diverse domains.
10 months newer

Llama 3.1 405B Instruct
Meta
2024-07-23

o3-pro
OpenAI
2025-06-10
Cost per million tokens (USD)

Llama 3.1 405B Instruct

o3-pro
Context window and performance specifications
o3-pro
2024-05-31
Available providers and their performance metrics

Llama 3.1 405B Instruct
Bedrock
DeepInfra
Fireworks
Hyperbolic

Llama 3.1 405B Instruct

o3-pro

Llama 3.1 405B Instruct

o3-pro
Lambda
Replicate
Together

o3-pro
OpenAI