GPT-5.5 Instant vs GPT-5.6 Sol
Pricing, benchmarks, and use case comparison
Quick take
- •GPT-5.5 Instant is meaningfully stronger at speed (92 vs 60 on our capability index).
- •GPT-5.6 Sol is meaningfully stronger at coding (97 vs 78).
Specs comparison
| GPT-5.5 Instant | GPT-5.6 Sol | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Type | Closed source | Closed source |
| Context window | ✓1050000 | Not announced |
| Input / 1M tokens | 5.00 | $5.00 |
| Output / 1M tokens | 30.00 | $30.00 |
| Release date | 2026-05 | 2026-06 |
Benchmarks
| Benchmark | GPT-5.5 Instant | GPT-5.6 Sol |
|---|---|---|
| AIME 2025 | 81.2 | - |
| Terminal-Bench 2.0 | 82.7 | - |
| FrontierMath Tier 1–3 | 51.7 | - |
| Terminal-Bench 2.1 | - | 88.8% |
| Terminal-Bench 2.1 (Ultra) | - | 91.9% |
| ExploitBench | - | competitive with Mythos Preview |
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 GPT-5.6 Sol if...
- →You are an approved preview partner needing the most capable model for agentic software engineering
- →Complex multi-step tasks that benefit from subagent orchestration (Ultra) or maximum reasoning depth (max)
- →Frontier scientific research, professional knowledge work, or security-sensitive workloads