> Calling it "GPT-5.1 Thinking" instead of o3-mini or whatever is interesting branding. They're trying to make reasoning models feel less like a separate product line and more like a mode. Smart move if they can actually make the router intelligent enough to know when to use it without explicit prompting.
Other providers have been using the same branding for a while. Google had Flash Thinking and Flash, but they've gone the opposite way and merged it into one with 2.5. Kimi K2 Thinking was released this week, coexisting with the regular Kimi K2. Qwen 3 uses it, and a lot of open source UIs have been branding Claude models with thinking enabled as e.g. "Sonnet 3.7 Thinking" for ages.
Other providers have been using the same branding for a while. Google had Flash Thinking and Flash, but they've gone the opposite way and merged it into one with 2.5. Kimi K2 Thinking was released this week, coexisting with the regular Kimi K2. Qwen 3 uses it, and a lot of open source UIs have been branding Claude models with thinking enabled as e.g. "Sonnet 3.7 Thinking" for ages.