Mistral Medium 3.5: pricing, context and performance

Overview

Mistral Medium 3.5 is a language model from Mistral AI, released on April 30, 2026. That makes it 6 months old as of October 22, 2026. Its weights are not published, so it only runs remotely, through the Mistral AI API or partner hosts (9 listed on models.dev). It has a reasoning mode: it can "think" before answering, which helps with multi-step problems but uses more tokens, and therefore more money.

We file it under mid-range models (34 models in this category on the site).

How much does Mistral Medium 3.5 cost?

Mistral Medium 3.5 costs $1.5 per million input tokens and $7.5 per million output tokens (median of 9 providers, checked on October 22, 2026).

In practice, an agent task that reads 20,000 tokens and writes 2,000 costs about $0.045, or $45 for 1,000 such tasks.

That is 1.7 times the median output price of mid-range models ($4.38).

To estimate your own budget, use the agent cost calculator.

What do independent benchmarks say?

Epoch AI publishes a single result for Mistral Medium 3.5 on our basket's benchmarks: too few to compute a reliable capability index.

• FrontierCode (advanced programming tasks): 8% — the best tracked model, Claude Opus 5.5, reaches 54.6%

Context and capabilities

Its context window reaches 262,144 tokens, roughly 393 pages of text at 500 words per page: enough for a long report or several contracts at once. A single answer can run to 209,715 tokens.

It accepts as input: text, image and PDF.

It can call tools (functions, APIs) and return structured JSON output, which makes it a possible foundation for an AI agent.

What is it good for?

Given its category, Mistral Medium 3.5 is mainly aimed at a balance between quality and cost, for everyday uses that do not justify a frontier model.

Before adopting it, test it on your own examples: benchmarks measure standard tasks, not your job.

Comparable models

In the same category, the models closest to Mistral Medium 3.5 are:

• Sonar Deep Research (Perplexity (Sonar), $8 per million output tokens)
• Gemini 3.5 Flash (Google DeepMind, index 76)
• Grok 4.7 (xAI, index 79.9)
• Grok 4.5 (xAI, index 79.1)