GPT-5.5 vs Mistral Medium 3.5
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
OpenAI · Apr 2026
OpenAI's flagship reasoning model with a 1M-token context window, built for hard coding, science and long-horizon agentic work.
Mistral AI · Mar 2026
Europe's strongest model line: frontier-adjacent quality at $0.40/$2 with EU data residency and on-prem options.
The verdict
These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. On price the gap is dramatic: Mistral Medium 3.5 works out roughly 14x cheaper per blended million tokens. GPT-5.5 also takes 1M of context versus 131K for Mistral Medium 3.5.
Specs & pricing
| GPT-5.5 | Mistral Medium 3.5 | |
|---|---|---|
| modhub Index | 77.2 | — |
| Input price / 1M | $5 | $0.4 |
| Output price / 1M | $30 | $2 |
| Context window | 1M | 131K |
| Max output | 128K | — |
| Open weights | no | no |
| Reasoning model | yes | no |
| Multimodal input | text, image | text, image |
| Knowledge cutoff | Jan 2026 | Dec 2025 |
| Released | Apr 2026 | Mar 2026 |
| Example monthly cost* | $95.00 | $7.00 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, GPT-5.5 or Mistral Medium 3.5?
- These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. On price the gap is dramatic: Mistral Medium 3.5 works out roughly 14x cheaper per blended million tokens. GPT-5.5 also takes 1M of context versus 131K for Mistral Medium 3.5.
- Which is cheaper, GPT-5.5 or Mistral Medium 3.5?
- GPT-5.5 costs $5/$30 per million input/output tokens, while Mistral Medium 3.5 costs $0.4/$2. For a typical workload of 10M input and 1.5M output tokens per month, that's $95.00 versus $7.00.
- Which model is better for coding, GPT-5.5 or Mistral Medium 3.5?
- We don't yet track SWE-bench Verified results for both models; check their individual pages for coding-related scores.