# Mistral Medium 3.5

Mistral Medium 3.5 is an AI model released by Mistral on Apr 29 2026. It has 128B parameters, a 256k context window and open weight. Tracked results include 77.6% on SWE-Bench Verified.

## Facts

| Field | Value |
| --- | --- |
| Model | Mistral Medium 3.5 |
| Developer | Mistral |
| Release date | Wednesday, Apr 29 2026 |
| Licensing | Open Weight |
| Parameters | 128B |
| Context window | 256k |

## API pricing

All rates in USD per 1,000,000 tokens, pay-as-you-go.

| Tier | Input | Cached input | Output |
| --- | --- | --- | --- |
| Standard | $1.50 | $0.15 | $7.50 |

Verified October 19, 2026 against the first-party source: https://mistral.ai/pricing/api/

## Tracked benchmark scores

| Benchmark | Score | Source | What it measures |
| --- | --- | --- | --- |
| SWE-Bench Verified | 77.6% | Lab | Real coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. |

## About Mistral Medium 3.5

Mistral Medium 3.5 was released in spring 2026 as a dense 128B model combining instruction following, reasoning, coding and image understanding. It supported a 256K-token context and configurable reasoning effort. Mistral described it as a merged flagship model, bringing several capabilities into one set of weights rather than requiring separate specialist models for each workflow.

The model became a foundation for coding and productivity work in Mistral Vibe and Le Chat. Its downloadable weights used a modified MIT License with conditions for companies above the specified revenue threshold. The release's practical focus was sustained work across tools and longer contexts, while its none and high reasoning settings allowed applications to choose how much deliberation a request received.

## Questions and answers

### When was Mistral Medium 3.5 released?

Mistral Medium 3.5 was released by Mistral on Wednesday, Apr 29 2026.

### Who made Mistral Medium 3.5?

Mistral Medium 3.5 was built by Mistral. French AI company building open and commercial models. Founded in 2023 by former Meta and DeepMind researchers.

### How much does Mistral Medium 3.5 cost?

Mistral Medium 3.5 costs $1.50 per million input tokens and $7.50 per million output tokens through the Mistral API. Cached input is $0.15 per million tokens. Rates are pay-as-you-go API prices verified against Mistral's published pricing on October 19, 2026.

### What benchmark scores did Mistral Medium 3.5 get?

Mistral Medium 3.5 reports 1 tracked benchmark score — SWE-Bench Verified: 77.6%. Tracked scores may come from lab reports or independent benchmarks; source details accompany the benchmark data.

### What is the context window of Mistral Medium 3.5?

Mistral Medium 3.5 has a context window of 256k. Providers may specify separate input and output token limits.

### How many parameters does Mistral Medium 3.5 have?

Mistral Medium 3.5 is reported at 128B parameters.

### Is Mistral Medium 3.5 open source?

Partly. Mistral Medium 3.5 is an open-weight model: the trained weights are free to download and run locally or on your own infrastructure, but the training data and code are not fully released and the license may restrict some commercial uses. It is not open source in the strict sense.

### What came before and after Mistral Medium 3.5?

Mistral's previous tracked release was Mistral Small 4 on Mar 16 2026, 44 days earlier. It was followed by Mistral Large 4 on Oct 6 2026.


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Canonical page: https://aireleasetracker.com/model/mistral/mistral-medium-3.5
Site index: https://aireleasetracker.com/llms.txt
Source: AI Release Tracker (https://aireleasetracker.com). Most benchmark scores come from lab launch material; gathered results identify the leaderboard that published them.