GPT-5.5 Pro
OpenAI
The premium reasoning tier of GPT-5.5 (April 2026), for the hardest agentic, coding, and knowledge-work tasks. Shares GPT-5.5's 1M-token context window and multimodal (text + vision) input, with extended reasoning for maximum accuracy.
Strengths
- Highest-accuracy tier of the GPT-5.5 generation for the hardest problems
- 1M-token context window with multimodal (text + vision) input
- Extended reasoning for complex agentic and knowledge-work tasks
Caveats
- Premium pricing and higher latency than standard GPT-5.5
- Overkill for routine tasks - GPT-5.5 or GPT-5.4 are more economical
- Vendor
- OpenAI
- Context Window
- 1,000,000 tokens
- Max Output
- 128,000 tokens
- License
- Proprietary
- Release Date
- 2026-04-23
- Training Cutoff
- 2025-12-01
- Modalities
- textimage
Capabilities
Vision
Audio
Video
Tool Use
Resources
Pricing
Premium reasoning tier priced above GPT-5.5; see OpenAI pricing for current rates.