Work with your files: PDFs, CSVs, and images
Goal. Upload a paper, a spreadsheet, or a figure and ask Claude questions about its actual contents instead of pasting text by hand.
Here's the PDF of a paper. Summarize the study design, the main result, and the single biggest limitation in three short paragraphs. Then quote the exact sentence where they state their primary outcome.
Click the attachment (paperclip / "Add files or photos") button below the message box, attach the file, then ask your question. Asking Claude to QUOTE the exact sentence keeps it honest and lets you verify against the source.
- 1Attach a file. Use the attachment button to add a PDF, Word doc, TXT, CSV, or an image (PNG/JPG/GIF/WebP). You can attach several files in one message.
- 2Ask about the content, not the file. "Which statistical test did they use and on what data?", "From this CSV, which sample has the highest variance?", "What does this gel image appear to show?"
- 3Demand quotes for anything load-bearing. Add "quote the exact sentence you're basing that on" — this turns a confident-sounding summary into something you can check against the original.
You'll see. Claude reading the document's real text and figures — answering, summarizing, and pulling exact quotes you can trace back to the page.
Cost. File upload works on the free plan. Limits to know: up to ~500MB and 20 files per chat; Claude reads text and visuals in PDFs under ~100 pages, and text-only for very long PDFs. Heavy use hits the free daily cap faster.
Takeaway. Stop copy-pasting — attach the PDF, CSV, or image and ask Claude about its contents directly, always asking it to quote the source for any claim that matters.