OpenAI: GPT-5.5
GPT-5.5 is OpenAI’s frontier model designed for complex professional workloads, building on GPT-5.4 with stronger reasoning, higher reliability, and improved token efficiency on hard tasks. It features a 1M+ token...
Everything else
| Max output | 128K |
|---|---|
| Input / 1M | $5 |
| Output / 1M | $30 |
| Cache read / 1M | $0.5 |
| Cache write / 1M | — |
| 1M in + 1M out | $35 |
| Takes | file, image, text |
| Returns | text |
| Tools | yes |
| Reasoning | optional · xhigh, high, medium, low, none |
| Open weights | no |
| Released | 2026-04-24 |
| Knowledge cutoff | 2025-12-01 |
| Retires | — |
| Catalog id | openai/gpt-5.5 |
Benchmarks
| source | epoch |
|---|---|
| eci | 158.46 |
| confidence | Likely |
| accessibility | API access |
| gpqa | 0.907 |
| gpqaStderr | 0.0175 |
Benchmark scores by Epoch AI, CC BY 4.0.
Using it
In 00, this model is picked per agent — and per tier, so the model that answers your customers need not be the one that writes your code. Get 00.