# Mistral Medium 3.1

> Mistral's cost-efficient frontier-class multimodal model for coding, STEM, and enterprise

- Maker: Mistral AI
- Line: Mistral Medium
- Canonical page: https://ai-tldr.dev/models/mistral-medium-3-1/
- Updated: 2026-06-18

## In short

Mistral Medium 3.1 (API id mistral-medium-2508, version 25.08) is Mistral AI's frontier-class multimodal model, released on August 12, 2025. It is an incremental refresh of Mistral Medium 3 that adds improvements in reasoning, coding, STEM, and tone control while keeping the same cost and deployment profile. It has a 128K-token context window and costs $0.40 per million input tokens and $2.00 per million output tokens.

## Facts

| Fact | Value | Source |
| --- | --- | --- |
| Context window | 128K | [1] |
| Input price | $0.40 / 1M tokens | [2] |
| Output price | $2.00 / 1M tokens | [2] |
| Licence | Proprietary (commercial API; enterprise self-hosted/in-VPC deployment available) · API only | [1] |
| Released | 12 August 2025 | [1] |

## Sources

1. [Mistral Medium 3.1 model card (official docs)](https://docs.mistral.ai/models/model-cards/mistral-medium-3-1-25-08)
2. [Medium is the new large — Mistral Medium 3 announcement](https://mistral.ai/news/mistral-medium-3/)

## Overview

Mistral Medium 3.1 (API id mistral-medium-2508, version 25.08) is Mistral AI's frontier-class multimodal model, released on August 12, 2025. It is an incremental refresh of Mistral Medium 3 that adds improvements in reasoning, coding, STEM, and tone control while keeping the same cost and deployment profile. The model accepts text and image input and returns text, with a 128K-token context window.

Mistral positions the Medium line under the banner 'Medium is the new large': it claims Medium 3 performs at or above 90% of Claude Sonnet 3.7 on benchmarks across the board, surpasses leading open models such as Llama 4 Maverick, and does so at roughly 8x lower cost. Pricing is $0.40 per million input tokens and $2.00 per million output tokens. Unlike the later Mistral Medium 3.5, Medium 3.1 is proprietary and is not released as open weights, though Mistral offers hybrid, on-premises, and in-VPC deployment for enterprise customers (four GPUs and above).

Mistral Medium 3.1 is available through Mistral's La Plateforme API as well as third-party gateways such as OpenRouter and the Vercel AI Gateway. It has since been deprecated (scheduled deprecation 2026-05-22, retirement 2026-08-31) in favor of Mistral Medium 3.5, the open-weight successor. Mistral has not published a detailed per-benchmark (MMLU/GPQA/HumanEval) breakdown for this version, so this page reports only the specifications the company and major model trackers have verified.

## Pricing

- Input: $0.40 / 1M tokens per 1M tokens
- Output: $2.00 / 1M tokens per 1M tokens

Pricing announced for the Mistral Medium 3 line and consistently reported for Medium 3.1 by Artificial Analysis, OpenRouter, and the Vercel AI Gateway.

Source: https://mistral.ai/news/mistral-medium-3/

## Strengths

- Strong coding and STEM performance for its price tier, a focus area Mistral highlights for the Medium line
- Cost-efficient: $0.40 input / $2.00 output per 1M tokens, roughly 8x cheaper than the frontier models Mistral benchmarks it against
- Multimodal: handles both text and image (vision) input
- 128K-token context window for long documents and codebases
- Flexible deployment, including hybrid, on-premises, in-VPC, and self-hosted on four GPUs and above for enterprises
- Improved tone, reasoning, and instruction-following over the original Mistral Medium 3

## Best for

- Coding assistance and code generation
- STEM reasoning and technical question answering
- Enterprise workflows requiring on-premises or in-VPC deployment
- Document and image understanding (vision input)
- Cost-sensitive production applications that need frontier-class quality at a mid-tier price
- Multilingual chat and content generation

## How to access

- [Mistral AI (La Plateforme)](https://docs.mistral.ai/models/model-cards/mistral-medium-3-1-25-08) — model id `mistral-medium-2508`
- [OpenRouter](https://openrouter.ai/mistralai/mistral-medium-3.1) — model id `mistralai/mistral-medium-3.1`
- [Vercel AI Gateway](https://vercel.com/ai-gateway/models/mistral-medium) — model id `mistral/mistral-medium`

## Mistral Medium versions

- [Mistral Medium 3.5](https://ai-tldr.dev/models/mistral-medium-3-5/) (28 April 2026)
- Mistral Medium 3.1 (12 August 2025) — this page
- [Mistral Medium 3](https://ai-tldr.dev/models/mistral-medium-3/) (7 May 2025)
- [Mistral Medium (2023)](https://ai-tldr.dev/models/mistral-medium-legacy/) (December 2023)

## FAQ

### When was Mistral Medium 3.1 released?

Mistral AI released Mistral Medium 3.1 on August 12, 2025. Its API identifier is mistral-medium-2508 (version 25.08).

### Is Mistral Medium 3.1 open weights?

No. Mistral Medium 3.1 is proprietary and available via API; its weights were not publicly released. The later Mistral Medium 3.5 is the open-weight successor in this line. Enterprises can, however, run Medium 3.1 through hybrid, on-premises, or in-VPC deployments arranged with Mistral.

### How much does Mistral Medium 3.1 cost?

It is priced at $0.40 per million input tokens and $2.00 per million output tokens, the same pricing Mistral announced for the Medium 3 line and roughly 8x cheaper than the frontier models Mistral compares it against.

### What is the context window and what modalities does it support?

Mistral Medium 3.1 has a 128K-token context window. It is multimodal, accepting both text and image (vision) input and producing text output.

## Links

- [Mistral Medium 3.1 model card (official docs)](https://docs.mistral.ai/models/model-cards/mistral-medium-3-1-25-08)
- [Medium is the new large — Mistral Medium 3 announcement](https://mistral.ai/news/mistral-medium-3/)
- [Mistral AI pricing](https://mistral.ai/pricing/)
- [Mistral Medium 3.1 — Artificial Analysis](https://artificialanalysis.ai/models/mistral-medium-3-1)
- [Mistral Medium 3.1 — OpenRouter](https://openrouter.ai/mistralai/mistral-medium-3.1)
- [Mistral Medium 3.1 — Vercel AI Gateway](https://vercel.com/ai-gateway/models/mistral-medium)

Source: AI/TLDR LLM registry, https://ai-tldr.dev/models/mistral-medium-3-1/