Choose for the next task
If you are sending a research summary to a colleague, PDF keeps the page layout together. If you are turning that same conversation into notes or documentation, Markdown gives you editable text. You can keep both when the original notes and the shared version serve different purposes.
Check code, formulas, and images
PDF is convenient for reading rendered formulas and tables, but inspect page breaks and wide code blocks before sharing. A fixed layout does not guarantee that every long line fits neatly on a page.
Markdown keeps headings, lists, and code as text. Formula rendering depends on the app that opens the file: an editor without the relevant math support may show LaTeX source instead of a typeset equation. Image references also need to remain accessible.
Export a sample in ChatShell
Open the conversation, open ChatShell, and select PDF or Markdown under Current Chat. Export the file and open it in the app you actually plan to use. Compare the first and last messages, one table, one code block, and any formulas or images with the original.
For PDF, ChatShell builds the file with its local PDF engine. It may download fonts; this is not the browser’s Print dialog. Enable image export if you need images, then check the result rather than assuming every attachment is included.
When another format fits better
Choose DOCX when someone needs to revise the document in Word. Choose JSON when you need structured conversation data for your own processing. An exported JSON file is not a promise that another service can import or restore the conversation.