Mistral Medium 3 vs o3-pro
Too close to call on our weighted score (Mistral Medium 3 53, o3-pro 51). The right pick depends on what you value most.
Mistral AIMistral Medium 3
53/100- ECI134.1
- Price$0.40 / $2.00
- Context131K
OpenAIo3-pro
51/100- ECI147.4
- Price$20.00 / $80.00
- Context200K
Add a model
Make it a three-way comparison.
Too close to call
It is close. Our weighted score puts them within 1 points (Mistral Medium 3 53/100, o3-pro 51/100), so choose by what matters most for your work: o3-pro for raw capability and Mistral Medium 3 on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- Capabilityo3-proCapabilities Index (ECI): o3-pro 147.4 · Mistral Medium 3 134.1
- Lowest priceMistral Medium 3Mistral Medium 3 $0.80 · o3-pro $35.00 per 1M tokens (3:1 blend)
- Longest contexto3-proo3-pro 200,000 · Mistral Medium 3 131,072 tokens
- Widest inputsSame inputsMistral Medium 3: Text, Images · o3-pro: Text, Images
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | Mistral Medium 3 | o3-pro |
|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 58 | 75 |
| Price | 25% | 54 | 0 |
| Inputs & features | 15% | 50 | 70 |
| Context window | 10% | 24 | 32 |
| Overall | 100% | 53/100 | 51/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Mistral Medium 3Mistral AI | o3-proOpenAI |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 134.1 | 147.4 (best) |
| ECI rank | #117 of 148 | #60 of 148 (best) |
| GPQA DiamondGraduate-level science questions | 59.5% | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 32.2% | — |
| Price per million tokens | ||
| Input | $0.40 (best) | $20.00 |
| Output | $2.00 (best) | $80.00 |
| Cached input | — | — |
| Blended (3:1) | $0.80 (best) | $35.00 |
| Long-context rate | Same rate | Same rate |
| Price source | Official Mistral API | Official OpenAI API |
| Limits | ||
| Context window | 131,072 tokens | 200,000 tokens (best) |
| Max output | 131,072 tokens (best) | 100,000 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | No | No |
| Audio | No | No |
| Video | No | No |
| Reasoning | No | Yeslow · medium · high |
| Tool calling | Yes | Yes |
| Structured output | No | Yes |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | mistral-medium-2505 | o3-pro |
| API providers | 5 | 6 (best) |
| Released | May 7, 2025 | Jun 10, 2025 |
| Knowledge cutoff | May 2025 | May 2024 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Mistral Medium 3$8.00
- o3-pro$360.00
Which should you choose?
Which is better: Mistral Medium 3 or o3-pro?
It is close. Our weighted score puts them within 1 points (Mistral Medium 3 53/100, o3-pro 51/100), so choose by what matters most for your work: o3-pro for raw capability and Mistral Medium 3 on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, Mistral Medium 3 or o3-pro?
Mistral Medium 3 is cheaper at $0.40 input / $2.00 output per million tokens (official Mistral 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 $0.80 per million tokens for Mistral Medium 3 versus $35.00 for o3-pro (44× as much).
Which scores higher on benchmarks?
o3-pro scores higher on the Capabilities Index (ECI): o3-pro 147.4 (#60 of 148) and Mistral Medium 3 134.1 (#117 of 148). Their confidence ranges do not overlap (145.8–149.7 vs 130.5–135.6), so the gap is a real one.
Which is better for coding?
There are no published SWE-bench Verified results for Mistral Medium 3 and o3-pro yet, so there is no like-for-like coding score. On overall capability, o3-pro 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 has the largest context window at 200,000 tokens, against 131,072 for Mistral Medium 3. Maximum output per response: Mistral Medium 3 up to 131,072, o3-pro up to 100,000 tokens.
Which can read images, PDFs, audio or video?
Mistral Medium 3 accepts text and images; o3-pro accepts text and images. They handle the same number of input types.
Are any of these open source?
No. Mistral Medium 3 and o3-pro are proprietary and only available through APIs and apps.
Which is newer?
o3-pro is the newest, released Jun 10, 2025. Mistral Medium 3 came out May 7, 2025. Knowledge cutoff: Mistral Medium 3 May 2025, o3-pro May 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.
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