Open the .zip you downloaded from ChatGPT or Claude. Find any old answer in seconds and save chats as Markdown. Your files are read inside this browser tab and never uploaded.
Images you uploaded or generated are shown when their files are inside the same .zip.
Attachments are listed by file name. Tool calls and extended thinking are hidden until you tick "Show tool calls and reasoning".
No. The file is opened with your browser's own file reader and processed in this tab. Nothing is sent to a server, and closing the tab clears it.
Usually, yes. Large files take a few seconds to open. If the tab struggles, unzip the export and open conversations.json on its own, which skips the images.
When you edit a message or regenerate an answer, ChatGPT keeps every branch. ChatShelf shows the branch you last saw, the same one the app shows.
Yes. Open one, then the other: the second file is added to the shelf, and duplicates are skipped.