Starting from iOS 18.1, you can set ChatGPT as the default search engine in Safari. Here’s how to use the LLM service for your browser queries.

Now you can set ChatGPT as the default search engine in Safari.
With Apple Intelligence in iOS 18, Apple provides OpenAI’s ChatGPT integration into several features of iOS. OpenAI also has a ChatGPT app (Free) which you can download from the App Store.
Once you have ChatGPT installed in iOS, you can use it as your default search engine within Safari.