Intro to Claude — Book 4 · Working With Your Files

The moment you stop typing and start handing things over. Every file type you can upload and the real size caps. Then the chapter that prevents the most confusion: what Claude actually *sees* inside each kind of file — because short PDFs are read visually, long ones are text only, and an image pasted into a Word document is invisible. How to interrogate a sixty-page contract you have not read, using specific questions rather than a summary request. The quote habit that turns a claim into something you can verify in three seconds. Photographs, screenshots and handwriting. Spreadsheets with blank rows and inconsistent spellings. And a clear page on what should never be uploaded anywhere, with the redaction that usually lets you ask anyway.