Combine multiple PDFs, split one into pages, or shrink file size — free, no signup, nothing ever uploaded.
Everything happens locally on your device using WebAssembly — your PDFs are never uploaded anywhere.
Combining and splitting PDFs are two of the most common document tasks — merging separate scanned pages or reports into a single file to send, or pulling specific pages out of a larger document without re-scanning anything. Both are simple structural operations (no re-rendering or quality loss involved), which is exactly why they can run entirely in your browser instead of needing a server.
These use a WebAssembly-powered PDF library to read each file's internal page structure, then copy the selected pages into a new PDF document — byte for byte, with no re-compression or quality loss. Text stays selectable, images stay at full resolution, and formatting is preserved exactly as it was in the original file.
Compress takes a fundamentally different approach: each page is rendered to an image and re-saved using a real WebAssembly build of mozjpeg (the same encoder behind tools like Google's Squoosh) at a quality level you control. This is extremely effective for scanned documents and image-heavy PDFs, which are almost always the source of huge file sizes — but it comes with a trade-off: text on the page is no longer selectable or searchable afterward, since it's now part of an image. If your PDF is mostly typed text and you need to keep it selectable, skip Compress and use Merge/Split, which never touch page content.