o3-pro vs Claude Opus 4.5
Claude Opus 4.5 comes out ahead, 55 to 51 on our weighted score, and it is the cheaper option too.
OpenAIo3-pro
51/100- ECI147.4
- Price$20.00 / $80.00
- Context200K
- Our pick
AnthropicClaude Opus 4.5
55/100- ECI150.1
- Price$5.00 / $25.00
- Context200K
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Make it a three-way comparison.
Claude Opus 4.5 is our pick
Claude Opus 4.5 is the better all-round choice, scoring 55/100 against o3-pro (51). It leads on capability, price and inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityClaude Opus 4.5Capabilities Index (ECI): Claude Opus 4.5 150.1 · o3-pro 147.4
- Lowest priceClaude Opus 4.5Claude Opus 4.5 $10.00 · o3-pro $35.00 per 1M tokens (3:1 blend)
- Longest contextAbout the sameo3-pro 200,000 · Claude Opus 4.5 200,000 tokens
- Widest inputsClaude Opus 4.5o3-pro: Text, Images · Claude Opus 4.5: Text, Images, PDFs
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | o3-pro | Claude Opus 4.5 |
|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 75 | 78 |
| Price | 25% | 0 | 2 |
| Inputs & features | 15% | 70 | 80 |
| Context window | 10% | 32 | 32 |
| Overall | 100% | 51/100 | 55/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | o3-proOpenAI | Claude Opus 4.5Anthropic |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 147.4 | 150.1 (best) |
| ECI rank | #60 of 148 | #48 of 148 (best) |
| GPQA DiamondGraduate-level science questions | — | 86.1% |
| FrontierMath Tiers 1–3Research-level mathematics | — | 34.4% |
| OTIS Mock AIME 2024–2025Competition mathematics | — | 86.1% |
| SWE-bench VerifiedFixing real GitHub issues | — | 76.7% |
| SimpleQA VerifiedShort factual questions | — | 45.7% |
| Price per million tokens | ||
| Input | $20.00 | $5.00 (best) |
| Output | $80.00 | $25.00 (best) |
| Cached input | — | $0.50 |
| Blended (3:1) | $35.00 | $10.00 (best) |
| Long-context rate | Same rate | Same rate |
| Price source | Official OpenAI API | Official Anthropic API |
| Limits | ||
| Context window | 200,000 tokens | 200,000 tokens |
| Max output | 100,000 tokens (best) | 64,000 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | No | Yes |
| Audio | No | No |
| Video | No | No |
| Reasoning | Yeslow · medium · high | Yeslow · medium · high |
| Tool calling | Yes | Yes |
| Structured output | Yes | Yes |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | o3-pro | claude-opus-4-5 |
| API providers | 6 | 28 (best) |
| Released | Jun 10, 2025 | Nov 24, 2025 |
| Knowledge cutoff | May 2024 | May 2025 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- o3-pro$360.00
- Claude Opus 4.5$100.00
Which should you choose?
Which is better: o3-pro or Claude Opus 4.5?
Claude Opus 4.5 is the better all-round choice, scoring 55/100 against o3-pro (51). It leads on capability, price and inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, o3-pro or Claude Opus 4.5?
Claude Opus 4.5 is cheaper at $5.00 input / $25.00 output per million tokens (official Anthropic API price). o3-pro costs $20.00 input / $80.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $10.00 per million tokens for Claude Opus 4.5 versus $35.00 for o3-pro (3.5× as much).
Which scores higher on benchmarks?
Claude Opus 4.5 scores higher on the Capabilities Index (ECI): Claude Opus 4.5 150.1 (#48 of 148) and o3-pro 147.4 (#60 of 148). The confidence ranges of the top two overlap (147.9–153.0 vs 145.8–149.7), so treat the gap as small.
Which is better for coding?
There are no published SWE-bench Verified results for o3-pro yet, so there is no like-for-like coding score. On overall capability, Claude Opus 4.5 leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.
Which has the bigger context window?
o3-pro and Claude Opus 4.5 share the same 200,000-token context window. Maximum output per response: o3-pro up to 100,000, Claude Opus 4.5 up to 64,000 tokens.
Which can read images, PDFs, audio or video?
o3-pro accepts text and images; Claude Opus 4.5 accepts text, images and PDFs. Claude Opus 4.5 handles the widest range of inputs.
Are any of these open source?
No. o3-pro and Claude Opus 4.5 are proprietary and only available through APIs and apps.
Which is newer?
Claude Opus 4.5 is the newest, released Nov 24, 2025. o3-pro came out Jun 10, 2025. Knowledge cutoff: o3-pro May 2024, Claude Opus 4.5 May 2025.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.
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