OpenAI has shipped over 30 new models, features, and tools through its API in the last six months-an average of one meaningful update every six days.
The flagship GPT-5.5 and GPT-5.5 Pro launched on April 23, priced at $5 per million input tokens and $30 per million output tokens. The company says these models are the top choices for complex coding and research tasks. In March, multiple GPT-5.4 variants-including mini and nano-arrived, tailored for high-volume workloads needing speed and cost efficiency.
Earlier audio model snapshots released in December 2025 improved multilingual support and reduced hallucinations.
Frequent deprecations of older models accompany the rapid releases, pushing developers to stay current. Meanwhile, OpenAI open-sourced a 1.5-billion-parameter Privacy Filter under Apache 2.0. The model lets developers mask personally identifiable information locally before data reaches OpenAI’s servers.
For the broader market, the pace creates both opportunity and risk. Startups can use GPT-5.5 Pro for demanding tasks and route simpler queries to nano-class models at lower cost. OpenAI’s push into specialized, cost-optimized variants threatens to commoditize capabilities that competitors sell at a premium.