I don’t think the model currently being tested in GPT-5.4 Pro is GPT-5.5 Pro.
— CHOI (@arrakis_ai) 19 avril 2026
That said, it does feel noticeably more capable while also being cheaper to run. However, rather than a direct successor to 5.4 Pro, it seems closer to a different class of model—something more in line… https://t.co/OYfS7vs5bc
I don’t think the model currently being tested in GPT-5.4 Pro is GPT-5.5 Pro. That said, it does feel noticeably more capable while also being cheaper to run. However, rather than a direct successor to 5.4 Pro, it seems closer to a different class of model—something more in line