Released 104 days after Mistral Large 3 · All Mistral releases
Mistral Small 4, released March 16 2026, is a Mixture-of-Experts model that consolidates the capabilities of Magistral (reasoning), Devstral (coding), and Mistral Small (instruct) into one versatile system. It has roughly 119B total parameters with about 6B active per token, so it stays efficient at inference while eliminating the need to choose between a fast chat model, a reasoning engine, and a multimodal assistant. With a 256K token context window and Apache 2.0 licensing, Small 4 accepts both text and image inputs for general chat, agentic tasks, and complex reasoning. A reasoning effort setting lets you trade response speed against depth. With reasoning enabled, Small 4 matches or surpasses GPT-OSS 120B on several reasoning benchmarks while producing significantly shorter outputs. The model is available across common inference stacks including NVIDIA NIM, vLLM, SGLang, llama.cpp, and Hugging Face Transformers, supporting both cloud and on-premise deployment. Small 4 is built for agentic AI, reasoning workflows, and code-intensive applications where a single adaptable model reduces operational complexity.
Call Mistral Small 4 on Opper with the OpenAI SDK. Sign up without a credit card. Get started
Mistral Small 4 runs on 2 different routes through the Opper gateway. Compare residency, zero data retention and training posture at a glance, with full data-handling detail per route below.
One of Mistral Small 4's 2 routes is on the monitoring board, so the figure below is that provider's availability rather than the model's.
Name a second model in the same request and the gateway tries it on retriable errors, so a busy hour never has to reach your users. Set up a fallback chain.
Measured over the last 30 days from each provider's official status feed via StatusGator. Refreshed hourly. 1 further route is not on the board yet. See uptime for every provider Opper monitors.
Each route hosting Mistral Small 4 has its own privacy posture, residency, and GDPR terms. Postures are maintained by Opper with a last-verification timestamp.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. EU; DPA available.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. EU; DPA available.
Independent benchmark scores — composite indices for reasoning, coding, and math, plus individual eval scores where available.
Call Mistral Small 4 through the Opper gateway with one API key. Opper is drop-in compatible with the OpenAI, Anthropic and Google AI SDKs.
Mistral Small 4 is a premium model on Opper. Sign up needs no credit card: you get an API key straight away and the free models work in the playground and the API. Add a card to use premium models, pay-as-you-go with no minimum.
Copy this and paste it into a coding agent like Claude Code, Cursor or Codex and it'll wire up Opper for you.
import OpenAI from "openai";const client = new OpenAI({apiKey: process.env.OPPER_API_KEY,baseURL: "https://api.opper.ai/v3/compat",});const completion = await client.chat.completions.create({model: "mistral-small-2603",messages: [{ role: "user", content: "Hello" }],});console.log(completion.choices[0].message.content);
Side-by-side on privacy, EU hosting, pricing, and benchmarks.
