Vellum examines every page of a scanned PDF, measures how much of its surface actually carries ink while ignoring a band around the edges — where a sheet feeder leaves a shadow or a dark rim — and shows the empty pages already ticked in a grid of thumbnails. A sensitivity slider moves the line between “truly blank” and “nearly empty”, and every tick box can be changed by hand before exporting. Kept pages are copied exactly as they are, with no rasterisation and no recompression: text, quality and original size survive untouched. Everything is computed by your browser, and no page is sent to a server.
Each page is rendered small and in grayscale, then Vellum counts the share of pixels clearly darker than the paper. The paper tone is estimated page by page, so a scan with a grey background is not counted as fully inked. A band along each edge is ignored, because a sheet feeder almost always leaves a shadow or a dark rim that would make an empty sheet look like a printed page.
Not at the default setting: it treats a page as blank below 0.15 % of inked surface, which absorbs dust and scanner noise but not a line of text. If on the contrary you want to discard pages carrying a single stray mention, raise the sensitivity slider and check the thumbnails, which show the measured ink for every page.
No. Vellum copies the kept pages into the new document exactly as they are: they are not rasterised, recompressed or re-encoded. Text stays selectable, images keep their resolution, and the file gets smaller by precisely what the removed pages weighed.
No. Both the analysis and the export are computed by your browser: no file is uploaded, nothing is kept, and the tool is free. That is what makes it usable on client files or medical records without any special clearance.
Vellum — free PDF tools whose processing stays on your device.