GPT-5.5 is OpenAI's frontier model for agentic coding, computer use, and scientific research, with High-rated cyber capability and self-optimizing inference.
Capabilities, design details, and architectural traits
GPT-5.5 is OpenAI's frontier model built for real, sustained work on a computer rather than single-turn chat. Instead of needing every step managed, it is designed to take a messy, multi-part task and carry it through planning, tool use, self-checking, and completion on its own.
| Trait | What Makes It Distinct |
|---|---|
| Speed without the usual tradeoff | GPT-5.5 matches its predecessor's per-token latency in real-world serving despite a large jump in capability, and finishes the same Codex tasks using significantly fewer tokens. |
| Self-optimizing inference stack | Through Codex, the model analyzed weeks of its own production traffic and wrote custom load-balancing heuristics for the infrastructure serving it, lifting token generation speed by over 20 percent. |
| High-risk capability rating | Cybersecurity and biological/chemical capability are rated High under the Preparedness Framework, paired with tighter classifiers on sensitive cyber requests and a Trusted Access for Cyber program for vetted defenders. |
| Framed as a co-scientist | Research capability is described as strong enough to act as a bona fide co-scientist in biomedical work, persisting through exploring an idea, gathering evidence, and interpreting results. |
| Mathematical research output | An internal version with a custom harness produced a new proof about off-diagonal Ramsey numbers in combinatorics, later verified in the Lean proof assistant. |
Early testers treated GPT-5.5 Pro less like a one-shot answer engine and more like a collaborator: critiquing manuscripts across multiple passes, stress-testing technical arguments, proposing follow-up analyses, and working directly with code, notes, and PDF context rather than producing a single response.
Independent evaluations · Artificial Analysis
Evaluate specifications, pricing, and independent benchmark indices
| Model Details | |||
|---|---|---|---|
| General Info | |||
| Provider | OpenAI | Anthropic | Anthropic |
| Release Date | April 23, 2026 | July 24, 2026 | June 9, 2026 |
| Knowledge Cutoff | Dec 2025 | May 2026 | - |
| Context & Limits | |||
| Context Window | 1.1M Best Context Window | 1M | 1M |
| Pricing (per 1M tokens) | |||
| Input Pricing | $5 Best Input Pricing | $5 Best Input Pricing | $10 |
| Output Pricing | $30 | $25 Best Output Pricing | $50 |
| Modalities | |||
| Inputs | fileimagetext | textimage | textimagefile |
| Outputs | text | text | text |
| Benchmarks (0-100) | |||
| Intelligence Index | 54.7 | 63.1 Best Intelligence Index | 62.1 |
| Coding Index | 71.6 | 78.0 Best Coding Index | 76.5 |
| Agentic Index | 45.9 | 59.2 Best Agentic Index | 56.6 |
Graduate-level reasoning and expert Q&A evaluation.
Extremely difficult logical reasoning and knowledge.
Logical reasoning over long context windows.
Independent evaluation data provided by Artificial Analysis. To view the latest benchmarks and full details, visit their official site.
