Drop in a PDF and shrink its file size. Nothing is uploaded anywhere; the file never leaves this browser tab.
Tap to choose a file
or drag one in
Shrink images finds the photos/scans embedded in the PDF, downsizes and recompresses just those, and leaves everything else — including live, selectable text — untouched. This is the safer default and works well for PDFs that are mostly text with a few images.
Rasterize pages redraws every page as a compressed image, the same approach used by "Match page sizes" in Merge. It works on anything, including scanned or image-heavy PDFs where "Shrink images" doesn't find much to shrink, but text stops being selectable, searchable, or copyable afterward.
Good balance of file size and visual quality for reading and printing.
How it works. This page loads MuPDF compiled to WebAssembly and rewrites the PDF in your browser's memory — the same engine desktop PDF tools use, just running locally instead of on a server. First load pulls down about 10 MB of engine files; after that it works from cache.