How to Compress a PDF (Reduce File Size)

Almost always, it's the images inside it, including scanned pages, embedded photos, or screenshots, and not the text. A ten-page text-only PDF is typically a few hundred kilobytes; the same PDF with full-resolution photos on every page can be tens of megabytes.

That's why compression tools target embedded images specifically: recompressing them at a slightly lower quality is where almost all the size reduction comes from.

Upload your PDF and choose a compression level: Light keeps quality closest to the original with a modest size reduction, Recommended balances the two, and Strong produces the smallest file at a visible quality tradeoff on images.

If your PDF is mostly text, such as a resume, a contract, or a report with no photos, expect a much smaller size reduction than a scanned or photo-heavy PDF, because there's little for compression to work on. That's expected, not a malfunction: this tool never returns a file larger than what you uploaded.

There's no exact-target-size mode. Try Strong first if you need the smallest possible file, for instance to fit an email attachment limit. If it's still too large, the PDF likely needs fewer or lower-resolution images to begin with, which compression alone can't fully solve.