+
+
+
+
+
+
+
+
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 leads with 71.1% higher average benchmark score. Llama 3.1 405B Instruct is available on 8 providers. Overall, Llama 3.1 405B Instruct is the stronger choice for coding tasks.
+
+
+
+
OpenAI
GPT-5 Codex is a language model developed by OpenAI. It achieves strong performance with an average score of 74.5% across 1 benchmarks. Notable strengths include SWE-Bench Verified (74.5%). Released in 2025, it represents OpenAI's latest advancement in AI technology.
+
+
+
+
Meta
Llama 3.1 405B Instruct is a language model developed by Meta. It achieves strong performance with an average score of 79.2% across 18 benchmarks. It excels particularly in ARC-C (96.9%), GSM8k (96.8%), API-Bank (92.0%). It supports a 256K token context window for handling large documents. The model is available through 8 API providers. Released in 2024, it represents Meta's latest advancement in AI technology.
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
Average performance across 19 common benchmarks
+
+
+
+
GPT-5 Codex
Average Score:3.9%
+
+
+
+
Llama 3.1 405B Instruct
Average Score:75.0%(+71.1%)
+
+
+
+
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:3.9%
Providers:0
+
+
+
+
Llama 3.1 405B Instruct
Avg Score:75.0%(+71.1%)
Providers:8