Practical use cases
- Confirming you grabbed the right file — the right version, the right page count — before running an operation you can't easily undo.
- Checking whether a scanned document has pages that are rotated or out of order, before deciding whether Rotate or Reorder is what you actually need.
What Preview does — and doesn't — do
Preview renders every page as a thumbnail using the same rendering technology the other tools use internally, so what you see reflects the file accurately, rotation included. It never writes anything: there's no save, download, or action button anywhere in this tool, because there's nothing for it to produce — it exists purely to let you look. Loading a file into Preview doesn't modify it in any way, and closing the tool discards the loaded copy from memory; nothing is kept between visits.
Common problems
- The file won't load: "This file appears to be corrupted or is not a valid PDF" or "This file is password protected" appear instead of thumbnails if the file can't be parsed.
- You expected your changes to carry over to another tool: they don't — Preview, Split, Delete, and every other tool are separate pages, each with its own file selection; nothing loaded here transfers automatically to another tool page.