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o3 vs Claude 3 Opus

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

Quick Verdict

o3 is cheaper than Claude 3 Opus at $10.00/1M/1M vs $15.00/1M/1M input tokens — a 1.5x cost difference. o3 scores higher on quality benchmarks (ELO 1380). Choose o3 for cost-sensitive workloads; both are strong choices depending on your budget.

Detailed Comparison

Metrico3Claude 3 Opus
Input Price / 1M tokens$10.00/1MCheaper$15.00/1M
Output Price / 1M tokens$40.00/1MCheaper$75.00/1M
Context Window200K200K
ELO Score (LMSYS)1380Smarter1249
Open Source
Free Tier
Release Date2025-042024-03

Which is cheaper: o3 or Claude 3 Opus?

o3 is the cheaper option at $10.00/1M per 1M input tokens, compared to $15.00/1M for Claude 3 Opus. That is a 1.5x cost difference on input tokens. Output pricing follows a similar pattern: o3 charges $40.00/1M/1M vs $75.00/1M/1M for Claude 3 Opus.

Which has better quality: o3 or Claude 3 Opus?

Based on LMSYS Chatbot Arena rankings, o3 achieves a higher ELO score (1380 vs 1249), suggesting stronger performance on open-ended tasks. o3 excels at highest reasoning benchmark scores of any model. Claude 3 Opus is known for best claude model for creative writing.

Which should you choose: o3 or Claude 3 Opus?

Choose o3 if:
  • Highest reasoning benchmark scores of any model
  • Better cost-efficiency than o1 at similar quality
  • Superior at agentic and multi-step tasks
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: o3 or Claude 3 Opus?

o3 is cheaper at $10.00/1M per 1M input tokens, making it 1.5x more affordable.

Which has better quality: o3 or Claude 3 Opus?

o3 scores higher on the LMSYS Chatbot Arena with an ELO of 1380, suggesting better overall quality for most tasks.

Which has a larger context window: o3 or Claude 3 Opus?

Both o3 and Claude 3 Opus have the same context window.

Should I choose o3 or Claude 3 Opus?

Choose o3 if cost is the priority. Choose o3 if benchmark quality is most important. Consider your specific use case: o3 is best for reasoning and math, while Claude 3 Opus excels at creative-writing and research.

Is o3 or Claude 3 Opus open source?

o3 is proprietary. Claude 3 Opus is proprietary.

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