Attach a PDF, Word document, spreadsheet, slide deck, CSV, JSON, HTML page, ZIP or source file and ask about it in the same message. The text is extracted and handed to the model as you send, so the answer is about your file. Spreadsheets arrive as tables so columns survive. If a file is too long for the model you picked, you are told it is an excerpt instead of getting a confident guess, and if a file cannot be read you are told that too. Web and mobile.