Crop PDF
Trim the margins of PDF pages: set how much to cut from each side, check the shaded preview and download. Runs in your browser; nothing is uploaded.
Cropping hides, it does not delete. It changes the visible page area (the crop box). Anything outside it stays inside the file and can be made visible again with other PDF software, so do not use cropping to remove private information.
Handy for removing wide white borders from scans or slides before printing or reading on a phone. Margins are measured as the page appears on screen, so rotated and landscape pages crop the way you expect.