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o3 vs Claude Sonnet 4.6

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

Quick Verdict

o3 is cheaper than Claude Sonnet 4.6 at $2.00/1M/1M vs $3.00/1M/1M input tokens — a 1.5x cost difference. o3 scores higher on quality benchmarks (ELO 1395). Choose o3 for cost-sensitive workloads; both are strong choices depending on your budget.

Detailed Comparison

Metrico3Claude Sonnet 4.6
Input Price / 1M tokens$2.00/1MCheaper$3.00/1M
Output Price / 1M tokens$8.00/1MCheaper$15.00/1M
Context Window200K1MLarger
ELO Score (LMSYS)1395Smarter1390
Open Source
Free Tier
Release Date2025-042025-10

Which is cheaper: o3 or Claude Sonnet 4.6?

o3 is the cheaper option at $2.00/1M per 1M input tokens, compared to $3.00/1M for Claude Sonnet 4.6. That is a 1.5x cost difference on input tokens. Output pricing follows a similar pattern: o3 charges $8.00/1M/1M vs $15.00/1M/1M for Claude Sonnet 4.6.

Which has better quality: o3 or Claude Sonnet 4.6?

Based on LMSYS Chatbot Arena rankings, o3 achieves a higher ELO score (1395 vs 1390), suggesting stronger performance on open-ended tasks. o3 excels at top-tier reasoning on math, science, and agentic tasks. Claude Sonnet 4.6 is known for best combination of speed and intelligence in the claude family.

Which should you choose: o3 or Claude Sonnet 4.6?

Choose o3 if:
  • Top-tier reasoning on math, science, and agentic tasks
  • 87% cheaper than original o1 at the same capability tier
  • 200K context window
Choose Claude Sonnet 4.6 if:
  • Best combination of speed and intelligence in the Claude family
  • 1M token context window at standard pricing
  • Extended thinking and adaptive thinking supported

Frequently Asked Questions

Which is cheaper: o3 or Claude Sonnet 4.6?

o3 is cheaper at $2.00/1M per 1M input tokens, making it 1.5x more affordable.

Which has better quality: o3 or Claude Sonnet 4.6?

o3 scores higher on the LMSYS Chatbot Arena with an ELO of 1395, suggesting better overall quality for most tasks.

Which has a larger context window: o3 or Claude Sonnet 4.6?

Claude Sonnet 4.6 has a larger context window at 1000K tokens.

Should I choose o3 or Claude Sonnet 4.6?

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 Sonnet 4.6 excels at coding and function-calling.

Is o3 or Claude Sonnet 4.6 open source?

o3 is proprietary. Claude Sonnet 4.6 is proprietary.

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