OpenAI gives GPT-5.5 Instant a readability upgrade while phasing out two older models

OpenAI is updating GPT-5.5 Instant to deliver more natural, better structured answers with fewer long bullet lists.

Canvas is being removed from GPT-5.5 Instant and GPT-5.5 Thinking, with writing and coding moved into chat blocks instead.

OpenAI is also phasing out o3 and GPT-4.5; both remain available to paying users for now, while o3 stays in the API.