Claude 3.5 Sonnet vs Llama 3.1 405B
Pricing, context window, and benchmark comparison · Last updated April 2026
Llama 3.1 405B is cheaper than Claude 3.5 Sonnet at $2.70/1M/1M vs $3.00/1M/1M input tokens — a 1.1x cost difference. Claude 3.5 Sonnet scores higher on quality benchmarks (ELO 1295). Choose Llama 3.1 405B for cost-sensitive workloads; choose Claude 3.5 Sonnet for maximum quality.
Which is cheaper: Claude 3.5 Sonnet or Llama 3.1 405B?
Llama 3.1 405B is the cheaper option at $2.70/1M per 1M input tokens, compared to $3.00/1M for Claude 3.5 Sonnet. That is a 1.1x cost difference on input tokens. Output pricing follows a similar pattern: Claude 3.5 Sonnet charges $15.00/1M/1M vs $2.70/1M/1M for Llama 3.1 405B.
Which has better quality: Claude 3.5 Sonnet or Llama 3.1 405B?
Based on LMSYS Chatbot Arena rankings, Claude 3.5 Sonnet achieves a higher ELO score (1295 vs 1267), suggesting stronger performance on open-ended tasks. Claude 3.5 Sonnet excels at 200k context window — best for long documents. Llama 3.1 405B is known for open source — can be self-hosted for data privacy.
Which should you choose: Claude 3.5 Sonnet or Llama 3.1 405B?
- → 200K context window — best for long documents
- → Industry-leading coding performance
- → Nuanced instruction following
- → Open source — can be self-hosted for data privacy
- → Competitive with GPT-4o on many benchmarks
- → Strong multilingual capabilities
Frequently Asked Questions
Which is cheaper: Claude 3.5 Sonnet or Llama 3.1 405B?
Llama 3.1 405B is cheaper at $2.70/1M per 1M input tokens, making it 1.1x more affordable.
Which has better quality: Claude 3.5 Sonnet or Llama 3.1 405B?
Claude 3.5 Sonnet scores higher on the LMSYS Chatbot Arena with an ELO of 1295, suggesting better overall quality for most tasks.
Which has a larger context window: Claude 3.5 Sonnet or Llama 3.1 405B?
Claude 3.5 Sonnet has a larger context window at 200K tokens.
Should I choose Claude 3.5 Sonnet or Llama 3.1 405B?
Choose Llama 3.1 405B if cost is the priority. Choose Claude 3.5 Sonnet if benchmark quality is most important. Consider your specific use case: Claude 3.5 Sonnet is best for coding and document-analysis, while Llama 3.1 405B excels at coding and research.
Is Claude 3.5 Sonnet or Llama 3.1 405B open source?
Claude 3.5 Sonnet is proprietary. Llama 3.1 405B is open source.