OpenAI
GPT-5.5
openai/gpt-5.5
Reliable reasoning for professional workloads, 1M context.
TextFiles, Images, Text → TextReady on endue
- Reasoning
- Long documents
Overview
Good for
Written by endue
- Reasoning
- Long documents
Not ideal for
From the model’s specs
Nothing in the specs rules out common agent work.
Capabilities
| Tool use | Supported |
|---|---|
| Structured output | Supported |
| JSON mode | Supported |
| Reasoning | Supported |
| Vision | Supported |
| Audio input | Not supported |
| Video input | Not supported |
| File input | Supported |
| Long context | Supported |
Specifications
- Model ID
openai/gpt-5.5- Family
- GPT-5
- Context window
- 1.1M tokens
- Input
- Files, Images, Text
- Output
- Text
- Released
- 2026-04-24