Mistral Small 4

• GPQA DiamondVery hard multiple-choice questions in biology, physics and chemistry, written by PhD experts. Random guessing scores 25%.47.5%#99 of 116
• AIME mathCompetition-level math problems in the style of the American Invitational Mathematics Examination. Share solved.5.8%#103 of 112

Benchmark data: Epoch AI, licensed CC BY 4.0

Companies that serve this model through an API: 4. Prices per million tokens, cheapest first.

Availability and prices come from OpenRouter’s public API and are refreshed daily. Uptime is the share of successful requests over the last 24 hours. Some providers run a compressed version of open models (fp8, int4), which is cheaper but can be slightly less accurate.

Call Mistral Small 4 through OpenRouter’s OpenAI-compatible API: create a key on openrouter.ai, then run one of these examples.

curl https://openrouter.ai/api/v1/chat/completions \
  -H "Authorization: Bearer $OPENROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "mistralai/mistral-small-2603", "messages": [{"role": "user", "content": "Hello! What can you do?"}]}'

import os
from openai import OpenAI

client = OpenAI(base_url="https://openrouter.ai/api/v1", api_key=os.environ["OPENROUTER_API_KEY"])
reply = client.chat.completions.create(
    model="mistralai/mistral-small-2603",
    messages=[{"role": "user", "content": "Hello! What can you do?"}],
)
print(reply.choices[0].message.content)

import OpenAI from "openai";

const client = new OpenAI({ baseURL: "https://openrouter.ai/api/v1", apiKey: process.env.OPENROUTER_API_KEY });
const reply = await client.chat.completions.create({
  model: "mistralai/mistral-small-2603",
  messages: [{ role: "user", content: "Hello! What can you do?" }],
});
console.log(reply.choices[0].message.content);

The same code works with every model on this site: only the model ID changes. Many labs also offer their own API and SDK.

• 1,000 chat replies

  ≈ 500 tokens in, 300 out each
  $0.255
• Summarise a 100-page document

  ≈ 50,000 tokens in, 1,000 out
  $0.0081
• An app with 10,000 requests a day for a month

  ≈ 1,000 tokens in, 400 out each
  $117

Cost calculator →

• Mistral AIOfficialSep 28, 2026

  Hallo, Deutschland!

• Mistral AIOfficialSep 16, 2026

  Mistral and Mozilla are bringing open, private and multilingual AI to your web browser

• Mistral AIOfficialSep 10, 2026

  Cloudera and Mistral Partner to Bring Specialized, Sovereign Intelligence to Enterprise Data

• Mistral AIOfficialSep 9, 2026

  Modernizing complex legacy code with AI agents.

• Mistral AIOfficialSep 8, 2026

  Mistral raises €3B to make sovereign, open-weight AI the technology frontier

How much does Mistral Small 4 cost?

Mistral Small 4 costs $0.15 per million input tokens and $0.60 per million output tokens through the API. For example, 1,000 chat replies of about 500 tokens in and 300 out cost around $0.255.

What is the context window of Mistral Small 4?

Mistral Small 4 can read up to 262,144 tokens in one request, about 492 pages of text. It can write up to 209,715 tokens in a single answer.

Is Mistral Small 4 open source?

Yes. Its weights are published (mistralai/Mistral-Small-4-119B-2603), so you can download it and run it on your own hardware, or use it through one of 4 API providers.

Who makes Mistral Small 4?

Mistral Small 4 is made by Mistral AI. It became available through the API on March 16, 2026.

Can Mistral Small 4 read images?

Yes. Besides text, it accepts images as input.

What are the alternatives to Mistral Small 4?

Models with a similar price from other companies include Perceptron Mk1.5, Qwen3.8 Omni Flash and GLM 5.3 Flash. You can compare them side by side on this page.