GPT-5.5 Instant vs GPT-5.6
Pricing, benchmarks, and use case comparison
Quick take
- •GPT-5.5 Instant is meaningfully stronger at speed (92 vs 72 on our capability index).
- •GPT-5.6 is meaningfully stronger at coding (94 vs 78).
Specs comparison
| GPT-5.5 Instant | GPT-5.6 | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Type | Closed source | Closed source |
| Context window | ✓1050000 | Not announced |
| Input / 1M tokens | 5.00 | 5 |
| Output / 1M tokens | 30.00 | 30 |
| Release date | 2026-05 | 2026-06 |
Benchmarks
| Benchmark | GPT-5.5 Instant | GPT-5.6 |
|---|---|---|
| AIME 2025 | 81.2 | - |
| Terminal-Bench 2.0 | 82.7 | - |
| FrontierMath Tier 1–3 | 51.7 | - |
| Terminal-Bench 2.1 (Sol) | - | 88.8% |
| Terminal-Bench 2.1 (Terra) | - | 82.5% |
| Terminal-Bench 2.1 (Luna) | - | 84.3% |
| Terminal-Bench 2.1 | - | 88.8 |
| ExploitBench | - | Competitive with Anthropic Mythos Preview |
| ExploitGym | - | Significant improvements |
| GeneBench v1 | - | Not announced |
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 if...
- →You want to standardize on one model generation but route requests across cost/quality tiers
- →You are an approved preview partner exploring the newest OpenAI capabilities
- →Workloads spanning agentic coding, knowledge work, and research where tier flexibility helps