OpenAI launches GPT-5.5, calling it “a new class of intelligence”

On Thursday, OpenAI released GPT-5.5 and GPT-5.5 Pro. The new model is, unsurprisingly, its most capable model yet.

After Anthropic launched Opus 4.7 a week ago, it was only a matter of time before OpenAI would follow suit — and, at least according to the benchmarks we’ve seen so far, GPT-5.5 and 5.5 Pro beat Opus 4.7 across many of today’s standard benchmarks. In many benchmarks, though, GPT-5.4 Pro still outperforms the default GPT-5.5.