GPT-5.5, GPT-5.5 Pro hit OpenAI API

This release signals OpenAI's move to close the reliability gap for agents through native multimodality and enhanced reasoning.

• –Native multimodal design eliminates the modular latency typically seen in vision-to-text pipelines.
• –"System 2" reasoning in the Pro model significantly reduces hallucinations in complex, multi-step logical chains.
• –Early performance on benchmarks like VoxelBench suggests a breakthrough in spatial reasoning and 3D environment manipulation.
• –Optimized inference speeds make the models viable for real-time, tool-use heavy applications.
• –Large context window improvements enable deeper reasoning over massive codebases and document sets.