GPT-5.5 Instant vs Mistral Large
Pricing, benchmarks, and use case comparison
Quick take
- •GPT-5.5 Instant is meaningfully stronger at speed (92 vs 70 on our capability index).
- •Mistral Large is 60% cheaper on input tokens, which compounds fast on high-volume or agentic workloads.
- •GPT-5.5 Instant has a 1050000 context window vs 128000 - better for whole-repo or long-document work.
Specs comparison
| GPT-5.5 Instant | Mistral Large | |
|---|---|---|
| Provider | OpenAI | Mistral AI |
| Type | Closed source | Closed source |
| Context window | ✓1050000 | 128000 |
| Input / 1M tokens | 5.00 | ✓2.00 |
| Output / 1M tokens | 30.00 | 6.00 |
| Release date | 2026-05 | 2024-02 |
Benchmarks
| Benchmark | GPT-5.5 Instant | Mistral Large |
|---|---|---|
| AIME 2025 | 81.2 | - |
| Terminal-Bench 2.0 | 82.7 | - |
| FrontierMath Tier 1–3 | 51.7 | - |
| MMLU | - | 84.0% |
| HumanEval | - | 92.0% |
Scores sourced from official provider release posts and independent benchmark aggregators.
Which should you choose?
Choose GPT-5.5 Instant if...
- →Interactive chat and everyday assistant tasks where responsiveness matters most
- →High-volume, latency-sensitive workloads that do not need deep reasoning
- →General questions, drafting, and summarization at speed
Choose Mistral Large if...
- →You need a strong European-built flagship with open weights
- →Your work is multilingual or requires nuanced reasoning
- →You want structured/JSON output and solid coding ability
- →You need the option to self-host for data sovereignty