Home/Compare/Claude 3.5 Sonnet vs Claude 3 Opus

Claude 3.5 Sonnet vs Claude 3 Opus

Pricing, context window, and benchmark comparison · Last updated April 2026

Quick Verdict

Claude 3.5 Sonnet is cheaper than Claude 3 Opus at $3.00/1M/1M vs $15.00/1M/1M input tokens — a 5.0x cost difference. Claude 3.5 Sonnet scores higher on quality benchmarks (ELO 1295). Choose Claude 3.5 Sonnet for cost-sensitive workloads; both are strong choices depending on your budget.

Detailed Comparison

MetricClaude 3.5 SonnetClaude 3 Opus
Input Price / 1M tokens$3.00/1MCheaper$15.00/1M
Output Price / 1M tokens$15.00/1MCheaper$75.00/1M
Context Window200K200K
ELO Score (LMSYS)1295Smarter1249
Open Source
Free Tier
Release Date2024-062024-03

Which is cheaper: Claude 3.5 Sonnet or Claude 3 Opus?

Claude 3.5 Sonnet is the cheaper option at $3.00/1M per 1M input tokens, compared to $15.00/1M for Claude 3 Opus. That is a 5.0x cost difference on input tokens. Output pricing follows a similar pattern: Claude 3.5 Sonnet charges $15.00/1M/1M vs $75.00/1M/1M for Claude 3 Opus.

Which has better quality: Claude 3.5 Sonnet or Claude 3 Opus?

Based on LMSYS Chatbot Arena rankings, Claude 3.5 Sonnet achieves a higher ELO score (1295 vs 1249), suggesting stronger performance on open-ended tasks. Claude 3.5 Sonnet excels at 200k context window — best for long documents. Claude 3 Opus is known for best claude model for creative writing.

Which should you choose: Claude 3.5 Sonnet or Claude 3 Opus?

Choose Claude 3.5 Sonnet if:
  • 200K context window — best for long documents
  • Industry-leading coding performance
  • Nuanced instruction following
Choose Claude 3 Opus if:
  • Best Claude model for creative writing
  • 200K context window
  • Deep, thoughtful long-form analysis

Frequently Asked Questions

Which is cheaper: Claude 3.5 Sonnet or Claude 3 Opus?

Claude 3.5 Sonnet is cheaper at $3.00/1M per 1M input tokens, making it 5.0x more affordable.

Which has better quality: Claude 3.5 Sonnet or Claude 3 Opus?

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 Claude 3 Opus?

Both Claude 3.5 Sonnet and Claude 3 Opus have the same context window.

Should I choose Claude 3.5 Sonnet or Claude 3 Opus?

Choose Claude 3.5 Sonnet 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 Claude 3 Opus excels at creative-writing and research.

Is Claude 3.5 Sonnet or Claude 3 Opus open source?

Claude 3.5 Sonnet is proprietary. Claude 3 Opus is proprietary.

Related Comparisons

o3 vs Claude 3.5 Sonnet
o3 vs Claude 3 Opus
DeepSeek R1 vs Claude 3.5 Sonnet
DeepSeek R1 vs Claude 3 Opus
o1 vs Claude 3.5 Sonnet
o1 vs Claude 3 Opus