o3 vs Claude Opus 4.1
o3 comes out ahead, 58 to 49 on our weighted score, and it is the cheaper option too.
- Our pick
OpenAIo3
58/100- ECI146.9
- Price$2.00 / $8.00
- Context200K
AnthropicClaude Opus 4.1
49/100- ECI144.1
- Price$15.00 / $75.00
- Context200K
Add a model
Make it a three-way comparison.
o3 is our pick
o3 is the better all-round choice, scoring 58/100 against Claude Opus 4.1 (49). It leads on capability, price and inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- Capabilityo3Capabilities Index (ECI): o3 146.9 · Claude Opus 4.1 144.1
- Lowest priceo3o3 $3.50 · Claude Opus 4.1 $30.00 per 1M tokens (3:1 blend)
- Longest contextAbout the sameo3 200,000 · Claude Opus 4.1 200,000 tokens
- Widest inputsSame inputso3: Text, Images, PDFs · Claude Opus 4.1: Text, Images, PDFs
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | o3 | Claude Opus 4.1 |
|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 74 | 71 |
| Price | 25% | 24 | 0 |
| Inputs & features | 15% | 80 | 70 |
| Context window | 10% | 32 | 32 |
| Overall | 100% | 58/100 | 49/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | o3OpenAI | Claude Opus 4.1Anthropic |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 146.9 (best) | 144.1 |
| ECI rank | #63 of 148 (best) | #81 of 148 |
| GPQA DiamondGraduate-level science questions | 81.8% (best) | 77.3% |
| FrontierMath Tiers 1–3Research-level mathematics | 33.3% (best) | 12.6% |
| OTIS Mock AIME 2024–2025Competition mathematics | 84.4% (best) | 68.9% |
| SWE-bench VerifiedFixing real GitHub issues | 62.3% | 73.4% (best) |
| SimpleQA VerifiedShort factual questions | 49.4% | — |
| Price per million tokens | ||
| Input | $2.00 (best) | $15.00 |
| Output | $8.00 (best) | $75.00 |
| Cached input | $0.50 | — |
| Blended (3:1) | $3.50 (best) | $30.00 |
| Long-context rate | Same rate | Same rate |
| Price source | Official OpenAI API | Median of 14 providers |
| Limits | ||
| Context window | 200,000 tokens | 200,000 tokens |
| Max output | 100,000 tokens (best) | 32,000 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | Yes | Yes |
| Audio | No | No |
| Video | No | No |
| Reasoning | Yeslow · medium · high | Yes |
| Tool calling | Yes | Yes |
| Structured output | Yes | No |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | o3 | — |
| API providers | 18 (best) | 14 |
| Released | Apr 16, 2025 | Aug 5, 2025 |
| Knowledge cutoff | May 2024 | Mar 31, 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$36.00
- Claude Opus 4.1$300.00
Which should you choose?
Which is better: o3 or Claude Opus 4.1?
o3 is the better all-round choice, scoring 58/100 against Claude Opus 4.1 (49). 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 or Claude Opus 4.1?
o3 is cheaper at $2.00 input / $8.00 output per million tokens (official OpenAI API price). Claude Opus 4.1 costs $15.00 input / $75.00 output per million tokens (median across 14 API providers). At a typical mix of three input tokens to one output token, that is $3.50 per million tokens for o3 versus $30.00 for Claude Opus 4.1 (8.6× as much).
Which scores higher on benchmarks?
o3 scores higher on the Capabilities Index (ECI): o3 146.9 (#63 of 148) and Claude Opus 4.1 144.1 (#81 of 148). The confidence ranges of the top two overlap (144.9–148.6 vs 141.6–146.0), so treat the gap as small. On individual benchmarks: GPQA Diamond — o3 81.8%, Claude Opus 4.1 77.3%; FrontierMath Tiers 1–3 — o3 33.3%, Claude Opus 4.1 12.6%; OTIS Mock AIME 2024–2025 — o3 84.4%, Claude Opus 4.1 68.9%; SWE-bench Verified — Claude Opus 4.1 73.4%, o3 62.3%.
Which is better for coding?
Claude Opus 4.1 resolves more real GitHub issues on SWE-bench Verified: Claude Opus 4.1 73.4% and o3 62.3%. Both support tool calling for agent workflows.
Which has the bigger context window?
o3 and Claude Opus 4.1 share the same 200,000-token context window. Maximum output per response: o3 up to 100,000, Claude Opus 4.1 up to 32,000 tokens.
Which can read images, PDFs, audio or video?
o3 accepts text, images and PDFs; Claude Opus 4.1 accepts text, images and PDFs. They handle the same number of input types.
Are any of these open source?
No. o3 and Claude Opus 4.1 are proprietary and only available through APIs and apps.
Which is newer?
Claude Opus 4.1 is the newest, released Aug 5, 2025. o3 came out Apr 16, 2025. Knowledge cutoff: o3 May 2024, Claude Opus 4.1 Mar 31, 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.
