Claude Sonnet 4vsMistral Medium 3.5
Claude Sonnet 4 | Mistral Medium 3.5 | |
|---|---|---|
| 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 |
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 |
| 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. | 72.7% | 77.6% |
| BenchmarksPublished by one model only | ||
BullshitBench v2Nonsense detection — Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. | 30% | — |
GPQA DiamondScience — Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 75.4% | — |
Arena Elo (Code)Community preference (code) — Like the text arena, but people vote on which AI writes better code. The votes become a chess-style Elo rating on arena.ai. Higher is better. | — | 1267 |
| Overview | ||
| Company | Anthropic | Mistral |
| Release date | May 22 2025 | Apr 29 2026 |
| Access | Proprietary | Open Weight |
Frequently asked questions
Mistral Medium 3.5 leads Claude Sonnet 4 on 1 of the 1 benchmark they both report (SWE-Bench Verified). Only Mistral Medium 3.5 has a verified first-party API price: $1.50 per million input tokens and $7.50 per million output tokens. No pay-as-you-go API rate is tracked for Claude Sonnet 4. Claude Sonnet 4 shipped 342 days before Mistral Medium 3.5, so benchmark comparisons should account for the intervening progress.
Claude Sonnet 4 is proprietary, while Mistral Medium 3.5 is open weight.
On SWE-Bench Verified, Mistral Medium 3.5 leads at 77.6% vs Claude Sonnet 4 at 72.7%.
Claude Sonnet 4 was released by Anthropic on May 22 2025.
Mistral Medium 3.5 was released by Mistral on Apr 29 2026.
Mistral Medium 3.5 leads on SWE-Bench Verified — Claude Sonnet 4 72.7% vs Mistral Medium 3.5 77.6%.
Only Mistral Medium 3.5 has a verified first-party API price: $1.50 per million input tokens and $7.50 per million output tokens. No pay-as-you-go API rate is tracked for Claude Sonnet 4. Rates are pay-as-you-go API prices verified on August 18, 2026.
Claude Sonnet 4 is a proprietary model released by Anthropic. Mistral Medium 3.5 is an open weight model released by Mistral.