+
+
+
+
+
+
+
+
VS
VS
VS
VS
VS
VS
GPT-5 Codex vs Llama 3.1 405B Instruct
Comprehensive side-by-side LLM comparison
Llama 3.1 405B Instruct is available on 8 providers. Both models have their strengths depending on your specific coding needs.
+
+
+
+
OpenAI
GPT-5 Codex was developed as a specialized variant of GPT-5 optimized for programming and software development tasks. Built to understand and generate code across multiple programming languages, it serves developers with enhanced capabilities for code completion, debugging, translation, and explanation of complex codebases.
+
+
+
+
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.
1 year newer
Llama 3.1 405B Instruct
Meta
2024-07-23
GPT-5 Codex
OpenAI
2025-09-15
+
+
+
+
+
+
+
+
+
+
+
+
Performance Metrics
Context window and performance specifications
+
+
+
+
Knowledge Cutoff
Training data recency comparison
GPT-5 Codex
2024-09-30
More recent knowledge cutoff means awareness of newer technologies and frameworks
Provider Availability & Performance
Available providers and their performance metrics
+
+
+
+
GPT-5 Codex
0 providers
+
+
+
+
Llama 3.1 405B Instruct
8 providers
Bedrock
+
+
+
+
GPT-5 Codex
Avg Score:0.0%
Providers:0
+
+
+
+
Llama 3.1 405B Instruct
Avg Score:0.0%
Providers:8