rashidazarang/chatgpt-chat-exporter ? reverse-engineered prompt

Build me a lightweight browser tool that lets me export my ChatGPT conversations, and also Google Gemini chats, into clean files I can keep or share.

I want it to work right in the browser with no account, no server, and nothing to install beyond maybe a simple userscript or paste into the console. It should capture the whole conversation, including long chats that load as I scroll, and keep the formatting looking right, like code blocks, tables, lists, links, math, timestamps, and any images or file references when possible.

The export should let me save as Markdown, HTML, or a print ready PDF. If there are images, it should handle them nicely instead of breaking the export. It should feel private and simple, ideally using the built in ChatGPT menu when available, and if not, a clear export button should appear. If you need to check current browser behavior or docs while building it, go ahead.