Custom GPT Brain Picker... You Can Now Choose the Exact ChatGPT Model

I am going to imagine that everyone reading my content uses custom GPTs already, so this is going to ne awesome news for you…

For a while, every custom GPT was stuck using the same brain… GPT‑4‑turbo, whether it needed it or not.

You can now choose the model inside your GPT.

Want a fast one, a smart one, a lightweight one… boom, pop it in…

Whatever fits the job.

That means for you…

No more using a Ferrari engine to send calendar invites.

No more slow, overkill GPTs for simple formatting tasks.

And most importantly no more blaming the tool when it just needed a better brain.

Here's how I'd do it…

• Use GPT‑4o‑mini for quick, high-volume stuff.

• Use GPT‑4o3 or GPT‑4.1 for deep, logical work that needs thinking power.

• Use GPT‑4o for anything with voice, vision, or real-time UX.

This sounds small, but it's massive.

You can now build smarter, cheaper, and more focused tools.

My move… Revisit your existing GPTs.

Are they doing grunt work with the most expensive brain?

Are they failing at logic when you could switch models?

Fix it.

One setting. Big shift…