Model Comparison

Claude Opus 4.5 vs o3Which is better in 2026?

Claude Opus 4.5 significantly outperforms across most benchmarks. o3 is 2.9x cheaper per token.

Verdict: Claude Opus 4.5 vs o3 — which is better?

Claude Opus 4.5 (by Anthropic) and o3 (by OpenAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Claude Opus 4.5 outperforms in 5 benchmarks (ARC-AGI v2, GPQA, SWE-Bench Verified, Tau2 Retail, Tau2 Telecom), while o3 is better at 0 benchmarks. Claude Opus 4.5 significantly outperforms across most benchmarks.

On price, o3 is roughly 2.9x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Choose Claude Opus 4.5 if…

  • you want the strongest raw capability — it leads on 5 of 5 shared benchmarks
  • you want the most recent training data — it shipped Nov 2025

Choose o3 if…

  • cost matters — it's about 2.9x cheaper per token
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Performance Benchmarks

Comparative analysis across standard metrics

5 benchmarks

Claude Opus 4.5 outperforms in 5 benchmarks (ARC-AGI v2, GPQA, SWE-Bench Verified, Tau2 Retail, Tau2 Telecom), while o3 is better at 0 benchmarks.

Claude Opus 4.5 significantly outperforms across most benchmarks.

Sun Jun 14 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

o3 costs less

For input processing, Claude Opus 4.5 ($5.00/1M tokens) is 2.5x more expensive than o3 ($2.00/1M tokens).

For output processing, Claude Opus 4.5 ($25.00/1M tokens) is 3.1x more expensive than o3 ($8.00/1M tokens).

In conclusion, Claude Opus 4.5 is more expensive than o3.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Sun Jun 14 2026 • llm-stats.com
Anthropic
Claude Opus 4.5
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
OpenAI
o3
Input tokens$2.00
Output tokens$8.00
Best providerOpenAI
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Context Window

Maximum input and output token capacity

Both models have the same input context window of 200,000 tokens. o3 can generate longer responses up to 100,000 tokens, while Claude Opus 4.5 is limited to 64,000 tokens.

Anthropic
Claude Opus 4.5
Input200,000 tokens
Output64,000 tokens
OpenAI
o3
Input200,000 tokens
Output100,000 tokens
Sun Jun 14 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Opus 4.5 and o3 support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Opus 4.5

Text
Images
Audio
Video

o3

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude Opus 4.5

Proprietary

Closed source

o3

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 4.5 was released on 2025-11-24, while o3 was released on 2025-04-16.

Claude Opus 4.5 is 7 months newer than o3.

Claude Opus 4.5

Nov 24, 2025

6 months ago

7mo newer
o3

Apr 16, 2025

1.2 years ago

Knowledge Cutoff

When training data ends

Claude Opus 4.5 has a knowledge cutoff of 2025-03-31, while o3 has a cutoff of 2024-05-31.

Claude Opus 4.5 has more recent training data (up to 2025-03-31), making it potentially better informed about events through that date compared to o3 (2024-05-31).

Claude Opus 4.5

Mar 2025

10 mo newer
o3

May 2024

Provider Availability

Claude Opus 4.5 is available from Anthropic. o3 is available from OpenAI.

Claude Opus 4.5

anthropic logo
Anthropic
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M

o3

openai logo
OpenAI
Input Price:Input: $2.00/1MOutput Price:Output: $8.00/1M
* Prices shown are per million tokens

Outputs Comparison

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Key Takeaways

Anthropic
Higher ARC-AGI v2 score (37.6% vs 6.5%)
Higher GPQA score (87.0% vs 83.3%)
Higher SWE-Bench Verified score (80.9% vs 69.1%)
Higher Tau2 Retail score (88.9% vs 80.2%)
Higher Tau2 Telecom score (98.2% vs 58.2%)
OpenAI
Less expensive input tokens
Less expensive output tokens
AnthropicClaude Opus 4.5
OpenAIo3
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Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude Opus 4.5
OpenAI
o3

FAQ

Common questions about Claude Opus 4.5 vs o3.

Which is better, Claude Opus 4.5 or o3?

Claude Opus 4.5 significantly outperforms across most benchmarks. Claude Opus 4.5 is made by Anthropic and o3 is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Opus 4.5 compare to o3 in benchmarks?

Claude Opus 4.5 scores Tau2 Telecom: 98.2%, MMMLU: 90.8%, Tau2 Retail: 88.9%, GPQA: 87.0%, SWE-Bench Verified: 80.9%. o3 scores COLLIE: 98.4%, AIME 2024: 91.6%, ARC-AGI: 88.0%, MathVista: 86.8%, AIME 2025: 86.4%.

Is Claude Opus 4.5 cheaper than o3?

o3 is 2.5x cheaper for input tokens. Claude Opus 4.5 costs $5.00/M input and $25.00/M output via anthropic. o3 costs $2.00/M input and $8.00/M output via openai.

What are the context window sizes for Claude Opus 4.5 and o3?

Claude Opus 4.5 supports 200K tokens and o3 supports 200K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Opus 4.5 and o3?

Key differences include input pricing ($5.00 vs $2.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 4.5 and o3?

Claude Opus 4.5 is developed by Anthropic and o3 is developed by OpenAI.

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