Mistral Medium 3.5 vs OpenAI o3
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
Mistral AI · Mar 2026
Europe's strongest model line: frontier-adjacent quality at $0.40/$2 with EU data residency and on-prem options.
OpenAI · Apr 2025
OpenAI's dedicated 2025 reasoning model that pioneered thinking-with-images and agentic tool use within chain-of-thought.
The verdict
These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. On price the gap is dramatic: Mistral Medium 3.5 works out roughly 4.4x cheaper per blended million tokens. OpenAI o3 also takes 200K of context versus 131K for Mistral Medium 3.5.
Specs & pricing
| Mistral Medium 3.5 | OpenAI o3 | |
|---|---|---|
| modhub Index | — | 68.9 |
| Input price / 1M | $0.4 | $2 |
| Output price / 1M | $2 | $8 |
| Context window | 131K | 200K |
| Max output | — | 100K |
| Open weights | no | no |
| Reasoning model | no | yes |
| Multimodal input | text, image | text, image |
| Knowledge cutoff | Dec 2025 | May 2024 |
| Released | Mar 2026 | Apr 2025 |
| Example monthly cost* | $7.00 | $32.00 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, Mistral Medium 3.5 or OpenAI o3?
- These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. On price the gap is dramatic: Mistral Medium 3.5 works out roughly 4.4x cheaper per blended million tokens. OpenAI o3 also takes 200K of context versus 131K for Mistral Medium 3.5.
- Which is cheaper, Mistral Medium 3.5 or OpenAI o3?
- Mistral Medium 3.5 costs $0.4/$2 per million input/output tokens, while OpenAI o3 costs $2/$8. For a typical workload of 10M input and 1.5M output tokens per month, that's $7.00 versus $32.00.
- Which model is better for coding, Mistral Medium 3.5 or OpenAI o3?
- We don't yet track SWE-bench Verified results for both models; check their individual pages for coding-related scores.