Claude Opus 4 vs Mistral Medium 3 vs o3-pro
Too close to call on our weighted score (Mistral Medium 3 53, o3-pro 51, Claude Opus 4 48). The right pick depends on what you value most.
AnthropicClaude Opus 4
48/100- ECI142.7
- Price$15.00 / $75.00
- Context200K
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
Too close to call
It is close. Our weighted score puts them within 1 points (Mistral Medium 3 53/100, o3-pro 51/100, Claude Opus 4 48/100), 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 · Claude Opus 4 142.7 · Mistral Medium 3 134.1
- Lowest priceMistral Medium 3Mistral Medium 3 $0.80 · Claude Opus 4 $30.00 · o3-pro $35.00 per 1M tokens (3:1 blend)
- Longest contextClaude Opus 4 and o3-proClaude Opus 4 200,000 · o3-pro 200,000 · Mistral Medium 3 131,072 tokens
- Widest inputsClaude Opus 4Claude Opus 4: Text, Images, PDFs · Mistral Medium 3: Text, Images · o3-pro: Text, Images
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Claude Opus 4 | Mistral Medium 3 | o3-pro |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 69 | 58 | 75 |
| Price | 25% | 0 | 54 | 0 |
| Inputs & features | 15% | 70 | 50 | 70 |
| Context window | 10% | 32 | 24 | 32 |
| Overall | 100% | 48/100 | 53/100 | 51/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Claude Opus 4Anthropic | Mistral Medium 3Mistral AI | o3-proOpenAI |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 142.7 | 134.1 | 147.4 (best) |
| ECI rank | #87 of 148 | #117 of 148 | #60 of 148 (best) |
| GPQA DiamondGraduate-level science questions | 76.3% (best) | 59.5% | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 64.4% (best) | 32.2% | — |
| SWE-bench VerifiedFixing real GitHub issues | 70.7% | — | — |
| Price per million tokens | |||
| Input | $15.00 | $0.40 (best) | $20.00 |
| Output | $75.00 | $2.00 (best) | $80.00 |
| Cached input | — | — | — |
| Blended (3:1) | $30.00 | $0.80 (best) | $35.00 |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Median of 5 providers | Official Mistral API | Official OpenAI API |
| Limits | |||
| Context window | 200,000 tokens (best) | 131,072 tokens | 200,000 tokens (best) |
| Max output | 32,000 tokens | 131,072 tokens (best) | 100,000 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | Yes | No | No |
| Audio | No | No | No |
| Video | No | No | No |
| Reasoning | Yes | No | Yeslow · medium · high |
| Tool calling | Yes | Yes | Yes |
| Structured output | No | No | Yes |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | — | mistral-medium-2505 | o3-pro |
| API providers | 5 | 5 | 6 (best) |
| Released | May 22, 2025 | May 7, 2025 | Jun 10, 2025 |
| Knowledge cutoff | Mar 31, 2025 | 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.
- Claude Opus 4$300.00
- Mistral Medium 3$8.00
- o3-pro$360.00
Which should you choose?
Which is better: Claude Opus 4, 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, Claude Opus 4 48/100), 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, Claude Opus 4, 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). Claude Opus 4 costs $15.00 input / $75.00 output per million tokens (median across 5 API providers); 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 $30.00 for Claude Opus 4 (38× as much) and $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), Claude Opus 4 142.7 (#87 of 148) and Mistral Medium 3 134.1 (#117 of 148). Their confidence ranges do not overlap (145.8–149.7 vs 140.2–144.2), 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. All three support tool calling for agent workflows.
Which has the bigger context window?
Claude Opus 4 and o3-pro have the largest context windows (200,000 and 200,000 tokens), against 131,072 for Mistral Medium 3. Maximum output per response: Claude Opus 4 up to 32,000, Mistral Medium 3 up to 131,072, o3-pro up to 100,000 tokens.
Which can read images, PDFs, audio or video?
Claude Opus 4 accepts text, images and PDFs; Mistral Medium 3 accepts text and images; o3-pro accepts text and images. Claude Opus 4 handles the widest range of inputs.
Are any of these open source?
No. Claude Opus 4, 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. Claude Opus 4 came out May 22, 2025; Mistral Medium 3 came out May 7, 2025. Knowledge cutoff: Claude Opus 4 Mar 31, 2025, 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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