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Mistral Medium 3.5 vs o1-pro

1 vs 0 benchmarks won

Mistral
Mistral Medium 3.5
OpenAI
o1-pro
Overview
CompanyMistralOpenAI
Release dateApr 29 2026Mar 19 2025
Model type
Open sourceYesNo
Specifications
Parameters
128B
Context window
256k
Benchmarks
Science reasoning
GPQA Diamond
Software engineering
SWE-Bench Verified
77.6%
Multimodal understanding
MMMU
Timeline
Release gapo1-pro shipped 406 days before Mistral Medium 3.5

Which is better: Mistral Medium 3.5 or o1-pro?

Mistral Medium 3.5 leads o1-pro on 1 of the tracked benchmarks (GPQA Diamond, SWE-Bench Verified, MMMU). o1-pro shipped 406 days before Mistral Medium 3.5, so benchmark comparisons should account for the intervening progress.

Mistral Medium 3.5 is an open-source / open-weight model; o1-pro is proprietary.

Direct benchmark comparisons are unavailable — at least one of these models has not published scores on GPQA Diamond, SWE-Bench Verified, or MMMU.

Frequently asked questions

When was Mistral Medium 3.5 released?
Mistral Medium 3.5 was released by Mistral on Apr 29 2026.
When was o1-pro released?
o1-pro was released by OpenAI on Mar 19 2025.
Is Mistral Medium 3.5 or o1-pro open source?
Mistral Medium 3.5 is an open-source / open-weight model released by Mistral. o1-pro is a proprietary model released by OpenAI.

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