> Mistral Small 3.1 is an open-weights AI model from Mistral, released 17 Mar 2025. Index score 107 (GPT-4 = 100), rank 170 of 229 ranked models. API price $0.35 in / $0.56 out per million tokens, 128K context.

[Models](https://themodelindex.org/models/) /[Mistral](https://themodelindex.org/labs/mistral/)

# Mistral Small 3.1

Mistral

Released 17 Mar 2025

Open

[Compare](https://themodelindex.org/compare/mistral-small-3-1-vs-o3-2025-04/)

10795–118

Index score

#170 of 229 models

1/ 8

Core tests taken

1 of 6 areas · plus 4 anchor tests

−29

Versus the frontier at release

best then: o1

Replaced by [Mistral Small 3.2](https://themodelindex.org/models/mistral-small-3-2/)

$0.35/ $0.56

Price per million tokens

input / output, list price

128K

Context window

tokens it reads at once

## Where it sits · on the frontier

_Chart: Model Index score of every scored model since late 2022, with the best closed and best open model over time_

GPT-4o reached this score 10 months earlier.

## Test results · by area · tick = best by any model

Show 4 anchor tests

Reasoning & knowledge

evidence

GPQA Diamond

47%

Humanity's Last Exam

no result

Maths

evidence

FrontierMath T1-3

no result

Coding

no evidence yet

SWE-bench Verified

no result

Terminal-Bench

no result

Agents

evidence

APEX-Agents

no result

Novel problems

no evidence yet

ARC-AGI-2

no result

Long tasks

no evidence yet

METR time horizon

no result

Independent results from the Epoch AI benchmarking hub, best reasoning setting. The core tests are shown here; anchor tests also inform the score and can be shown above.

## What others say · rank on each leaderboard

The Model Index

independent tests, our method

#170

of 219 · 107

Epoch Capabilities Index

overall capability from many benchmarks

#143

of 239 · 127.5

Further left is better. Leaderboards measure different things: LMArena is people voting blind between two answers, the others are test scores. Click any row for the source.

## Best at · top three among current models

Replaced by Mistral Small 3.2; it no longer leads any category among current models.

Where this model places in the top three of today's models, on category leaderboards and on our core tests.

## Where to use it · prices checked 1 Oct 2026

#### From the lab

Le Chat

app · subscription

↗

Mistral API

API

↗

#### API providers · 1 · per million tokens, in / out

C

Cloudflare

$0.35 / $0.56

cheapest

#### Run it yourself

🤗

Official weights

mistralai/Mistral-Small-3.1-24B-Instruct-2503

↗

Provider prices come from OpenRouter's live listing; going direct to a provider can differ. Subscriptions are the lab's own apps.

## Facts and sources

Released

17 Mar 2025

Announcement

not linked yet

Release entry

–

Scored as

Mistral Small 3.1

Artificial Analysis index

–

Output speed

–

Hugging Face

[mistralai/Mistral-Small-3.1-24B-Instruct-2503 ↗](https://huggingface.co/mistralai/Mistral-Small-3.1-24B-Instruct-2503)

## Mistral releases · around this one

Mistral 7B

Open

27 SEP 2023

index 83

Mixtral 8x7B

Open

8 DEC 2023

index 88

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Source: https://themodelindex.org/models/mistral-small-3-1/ · The Model Index · data as of 2026-10-01