OpenAI launched GPT-5.5 on April 23, billing it as their most capable model to date - faster than GPT-5 and built specifically for demanding, multi-step work: coding, research, and data analysis that spans multiple tools in a single session.
The speed improvement matters more now than it would have a year ago. AI agents - where a model runs a sequence of steps on its own, like searching the web, writing code, analyzing results, and producing a summary - mean that latency multiplies across every step in a chain. A model that responds faster on each step in a 30-step task cuts total completion time by a meaningful amount. OpenAI is clearly building GPT-5.5 with those workflows in mind.
The "across tools" framing in the announcement points to tighter integration with OpenAI's expanding tool ecosystem: code execution, web search, file analysis, and external API connections. ChatGPT Pro and Plus subscribers will likely get access first, following OpenAI's standard rollout pattern for major model releases.
Benchmark numbers and technical details weren't included in the initial blog post - those typically surface in the days after launch as OpenAI publishes evaluation results and developers run their own tests. The clearest signal from the announcement is where OpenAI wants this model to compete: complex, multi-step professional tasks rather than casual back-and-forth conversation.