AI Model Release Tracker - Timeline of Major AI Models from 2022-2026

Mistral Medium 3.5 vs o1

Mistral
Mistral Medium 3.5
OpenAI
o1
Overview
CompanyMistralOpenAI
Release dateApr 29 2026Dec 5 2024
Model type
Open sourceYesNo
Specifications
Parameters
128B
Context window
256k
Benchmarks
Coding
SWE-Bench Verified
77.6%
Timeline
Release gapo1 shipped 510 days before Mistral Medium 3.5

Which is better: Mistral Medium 3.5 or o1?

Mistral Medium 3.5 and o1 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. o1 shipped 510 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 is proprietary.

Direct benchmark comparisons are unavailable — Mistral Medium 3.5 and o1 don't publish scores on any of the same benchmarks.

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 released?
o1 was released by OpenAI on Dec 5 2024.
Is Mistral Medium 3.5 or o1 open source?
Mistral Medium 3.5 is an open-source / open-weight model released by Mistral. o1 is a proprietary model released by OpenAI.

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