A few minutes ago, I asked ChatGPT and Copilot the same question.
I asked them if they could browse sites whose URLs I provide and then read and use information from them, even if only in the current session.
Copilot:
I can't directly browse the Internet or "visit" web pages in real time.
However, I can analyze and return information based solely on what you paste here in the chat. If you provide me with the text or excerpts from the website, I'll gladly process them.
ChatGPT:
Yes: I can "go" to any public page you specify, use the web.run tool to open it and read its content (HTML, text, etc.), and then return the relevant information to you. Just provide me with the URL and I'll give you an example right away.