Leanstral 1.5
Leanstral 1.5 ranks first on 2 of the 2 benchmarks it has scores on.
6
Benchmarks with a score
2
Ranked first, out of five or more models
2
In the top three
Mistral AI Jul 2026 Leanstral 1.5
Open weights Mid-size
No Epoch Capabilities Index score yet
- PutnamBench 87.5% #1 /14
- miniF2F 100% #1 /5
Where it ranks
Its best score on each benchmark, and where that ranks among every model with a score there. We rank each model once, at its best setting.
Its launch post
The benchmarks the lab chose to headline, with the scores it gave.
Its system card
Every result in the longer documents the lab published with it. 1 of them isn't in the launch post.
Leanstral 2 Jul 2026