
Mistral: Mistral Medium 3.5
mistralai/mistral-medium-3-5
Model weightsMistral Medium 3.5 is a dense 128B instruction-following model from Mistral AI. It supports text and image inputs with text output, and is designed for agentic workflows, coding, and complex multi-step reasoning. It is particularly strong at reliable multi-tool calling and long-horizon tasks, with a 256K context window, configurable reasoning effort per request, and a custom vision encoder that handles variable image sizes and aspect ratios. Self-hostable on as few as four GPUs and available under open weights.
Providers
Different companies host the same model. OpenRouter routes your request to one of them based on the routing mode you pick: Balanced (price + speed), Nitro (fastest), or Floor (cheapest).
| $1.65 | $8.25 | 0.69s | 82 tok/s | ||
| $1.50 | $7.50 | 0.97s | 72 tok/s |
Input $1.65 / Output $8.2582 tok/s100.00% uptime
Input $1.50 / Output $7.5072 tok/s99.97% uptime
Pricing
The average price customers actually pay for this model, next to the prices providers post. Caching and discounts mean the price actually paid is often well below the listed one.
Weighted average
Mistral Medium 3.5 — Price history
| $1.50 | $7.50 | 66.0% | 78.3% | ||
| $1.65 | $8.25 | 53.5% | 21.7% |
- Effective in $1.50 / Effective out $7.50Token share78.3%
- Effective in $1.65 / Effective out $8.25Token share21.7%
Performance
Throughput is how fast the model writes (tokens per second — higher is better). Latency is total round-trip time (lower is better). TTFT is time-to-first-token — how long before you see anything appear (lower is better).
P50, best across providers
P50, best provider
Uptime
Uptime is the percentage of the past 3 days that at least one provider was responding to requests. Availability is the percentage of time that inference was successfully served. OpenRouter continuously monitors and uses the next-best provider when one returns an error.
Availability over the last 3 days
Last 72 hoursAvailability over the last 24 hours
When an error occurs in an upstream provider, we can recover by routing to another healthy provider, if your request filters allow it. You can access per-provider uptime data programmatically through the Endpoints API. Learn more about our load balancing and provider routing options.
Benchmarks
Scores on standardized evaluations and this model’s own outputs on shared benchmark prompts. Higher percentages are better — and each rank shows where this model lands among the models evaluated on that source.
| Source | Benchmark | Score |
|---|---|---|
| Artificial Analysis | Mistral Medium 3.5 Intelligence Index | 4.6 |
| Artificial Analysis | Mistral Medium 3.5 Coding Index | 46.9 |
| Artificial Analysis | Mistral Medium 3.5 Agentic Index | 7.0 |
| Artificial Analysis | Mistral Medium 3.5 GPQA Diamond | 74.8% |
| Artificial Analysis | Mistral Medium 3.5 HLE | 13.8% |
| Artificial Analysis | Mistral Medium 3.5 IFBench | 68.8% |
| Artificial Analysis | Mistral Medium 3.5 τ²-Bench Telecom | 94.2% |
| Artificial Analysis | Mistral Medium 3.5 AA-LCR | 69.3% |
| Artificial Analysis | Mistral Medium 3.5 τ-Bench Banking | 15.1% |
| Artificial Analysis | Mistral Medium 3.5 GDPval-AA | 13.4% |
| Artificial Analysis | Mistral Medium 3.5 CritPt | 0.0% |
| Artificial Analysis | Mistral Medium 3.5 SciCode | 40.2% |
| Artificial Analysis | Mistral Medium 3.5 Terminal-Bench Hard | 33.3% |
| Artificial Analysis | Mistral Medium 3.5 Terminal-Bench 4.0 | 0.0% |
| Artificial Analysis | Mistral Medium 3.5 Terminal-Bench 2.1 | 50.6% |
| Artificial Analysis | Mistral Medium 3.5 AA-Omniscience Accuracy | 23.0% |
| Artificial Analysis | Mistral Medium 3.5 AA-Omniscience Non-Hallucination Rate | 19.8% |
Apps
Public apps that send the most traffic to this model. Good signal for what real production workloads look like — and a hint at which use cases this model is best suited for.
Activity
Token volume and request traffic to this model over time.
API
Drop-in code to call this model. OpenRouter's API is OpenAI-compatible — most SDKs work by just swapping the base URL. The only thing that changes between models is the model slug below.
Available through EU in-region routing
Mistral: Mistral Medium 3.5 is available through EU in-region routing. Requests sent to eu.openrouter.ai are decrypted in the EU and routed only to shared provider endpoints in Europe (the EU/EEA, the UK, and Switzerland).
- Providers in Europe
- Mistral
- Prices in Europe
- Mistral: $1.65/M tokens input, $8.25/M tokens output
- Base URL
https://eu.openrouter.ai/api/v1- Plan
- Requires Business or Enterprise. Self-serve on Business: no contract, no monthly minimum. OpenRouter Business for EU in-region routing
Fails closed: if no shared provider endpoint in Europe is available, the request errors instead of leaving the region. Requests served by your own BYOK key go to your deployment’s region, which you control. In-region routing docs
Frequently asked questions
Mistral Medium 3.5 is a dense 128B instruction-following model from Mistral AI. It supports text and image inputs with text output, and is designed for agentic workflows, coding, and complex multi-step reasoning.
Mistral Medium 3.5 costs $1.50/M input tokens and $7.50/M output tokens.
Mistral Medium 3.5 has a 262,144 token context window. It supports up to 262,144 completion tokens.
Yes. Mistral Medium 3.5 accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.
Mistral Medium 3.5 accepts text, images, and files such as PDFs as input and returns text.
Mistral Medium 3.5 is served by 1 provider on OpenRouter: Mistral.
Mistral Large 4, Mistral Small 4, Devstral 2 2512 and 16 more are other text models from Mistral.
Mistral Medium 3.5 was released on April 30, 2026.