[layer8]

This has been in ChatGPT from pretty early on? Just edit any prompt, it creates a new branch, and you can switch back and forth.

[b800h]

Blimey, I didn't realise the entire thread was saved when you edited a prompt. Very good! Mind you, it feels "unsafe". I'd like to be able to clone a thread.

[cruffle_duffle]

You can toggle between different branches in both GPT and Claude.