o3-pro vs GPT-5.1
GPT-5.1 comes out ahead, 60 to 51 on our weighted score, and it is the cheaper option too.
GPT-5.1 is our pick
GPT-5.1 is the better all-round choice, scoring 60/100 against o3-pro (51). It leads on capability, price and context window. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGPT-5.1Capabilities Index (ECI): GPT-5.1 149.7 · o3-pro 147.4
- Lowest priceGPT-5.1GPT-5.1 $3.44 · o3-pro $35.00 per 1M tokens (3:1 blend)
- Longest contextGPT-5.1GPT-5.1 400,000 · o3-pro 200,000 tokens
- Widest inputsSame inputso3-pro: Text, Images · GPT-5.1: Text, Images
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | o3-pro | GPT-5.1 |
|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 75 | 78 |
| Price | 25% | 0 | 24 |
| Inputs & features | 15% | 70 | 70 |
| Context window | 10% | 32 | 44 |
| Overall | 100% | 51/100 | 60/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification |  o3-proOpenAI | GPT-5.1OpenAI |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 147.4 | 149.7 (best) |
| ECI rank | #60 of 148 | #52 of 148 (best) |
| GPQA DiamondGraduate-level science questions | — | 87.6% |
| OTIS Mock AIME 2024–2025Competition mathematics | — | 88.6% |
| SWE-bench VerifiedFixing real GitHub issues | — | 68.0% |
| SimpleQA VerifiedShort factual questions | — | 48.0% |
| Price per million tokens | ||
| Input | $20.00 | $1.25 (best) |
| Output | $80.00 | $10.00 (best) |
| Cached input | — | $0.125 |
| Blended (3:1) | $35.00 | $3.44 (best) |
| Long-context rate | Same rate | Same rate |
| Price source | Official OpenAI API | Official OpenAI API |
| Limits | ||
| Context window | 200,000 tokens | 400,000 tokens (best) |
| Max output | 100,000 tokens | 128,000 tokens (best) |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | No | No |
| 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 | gpt-5.1 |
| API providers | 6 | 21 (best) |
| Released | Jun 10, 2025 | Nov 13, 2025 |
| Knowledge cutoff | May 2024 | Sep 30, 2024 |
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
- GPT-5.1$32.50
Which should you choose?
Which is better: o3-pro or GPT-5.1?
GPT-5.1 is the better all-round choice, scoring 60/100 against o3-pro (51). It leads on capability, price and context window. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, o3-pro or GPT-5.1?
GPT-5.1 is cheaper at $1.25 input / $10.00 output per million tokens (official OpenAI 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 $3.44 per million tokens for GPT-5.1 versus $35.00 for o3-pro (10× as much).
Which scores higher on benchmarks?
GPT-5.1 scores higher on the Capabilities Index (ECI): GPT-5.1 149.7 (#52 of 148) and o3-pro 147.4 (#60 of 148). The confidence ranges of the top two overlap (148.3–151.1 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, GPT-5.1 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?
GPT-5.1 has the largest context window at 400,000 tokens, against 200,000 for o3-pro. Maximum output per response: o3-pro up to 100,000, GPT-5.1 up to 128,000 tokens.
Which can read images, PDFs, audio or video?
o3-pro accepts text and images; GPT-5.1 accepts text and images. They handle the same number of input types.
Are any of these open source?
No. o3-pro and GPT-5.1 are proprietary and only available through APIs and apps.
Which is newer?
GPT-5.1 is the newest, released Nov 13, 2025. o3-pro came out Jun 10, 2025. Knowledge cutoff: o3-pro May 2024, GPT-5.1 Sep 30, 2024.
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.
Related comparisons
- Add Claude Opus 4.1Three-way comparison
- o3-pro vs Claude Opus 4.1Anthropic · ECI 144.1
- o3-pro vs Gemini 2.5 ProGoogle · ECI 145.3
- o3-pro vs InklingThinking Machines · ECI 148.6
- o3-pro vs DeepSeek-R1-Distill-Qwen-32BDeepSeek · ECI 137.4
- GPT-5.1 vs Qwen3.6 Max PreviewAlibaba (Qwen) · ECI 149.2
- GPT-5.1 vs Gemini 3 Pro PreviewGoogle · ECI 153.0
