Compare AI models
| Specifications | ||
ParametersA rough measure of how big the model is. More parameters usually means more capable and more expensive to run, though it is a poor guide on its own — a smaller, newer model often beats a larger, older one. | 128B | — |
Context windowHow much text the model can hold in mind at once — your question, any documents you attach, the conversation so far, and its own reply. Go past it and the earliest part falls out of view. | 256k | — |
| API pricingUSD per 1M tokens · lower wins | ||
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it. | $1.50 | $1.10 |
Output priceWhat you pay for the text the model writes back. It is normally the dearer half: producing an answer costs more than reading one. | $7.50 | $4.40 |
Cached input priceA reduced rate for text you send over and over. If every request starts with the same instructions or the same document, the provider keeps a copy ready and charges less to read it again. | — | $0.55 |
Cheapest inputLowest input rate across every provider on OpenRouter, the lab included. The cheapest endpoint may run a quantised build or a shorter context — see "Available from" on the model page. | $1.50Mistral | $1.10OpenAI |
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input. | $7.50Mistral | $4.40OpenAI |
| $675Mistral list price | $440OpenAI list price | |
| Benchmarks | ||
SWE-Bench VerifiedCoding — 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. | 77.6% | 49.3% |
| Overview | ||
| Company | Mistral | OpenAI |
| Release date | Apr 29 2026 | Jan 31 2025 |
| Access | Open Weight | Closed |
| Model details | View model | View model |
Other comparisons
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Mistral Medium 3.5 leads o3-mini on 1 of the 1 benchmark they both report (SWE-Bench Verified). o3-mini is cheaper on both input and output: $1.10 vs $1.50 per million input tokens, and $4.40 vs $7.50 per million output tokens. o3-mini shipped 453 days before Mistral Medium 3.5, so benchmark comparisons should account for the intervening progress.
Mistral Medium 3.5 is open weight, while o3-mini is closed.
On SWE-Bench Verified, Mistral Medium 3.5 leads at 77.6% vs o3-mini at 49.3%.