Comprimi PDF Online

Why PDFs get large, and how compression helps

PDF file size is usually dominated by embedded images and fonts, plus redundant internal structure. This tool shrinks a PDF by optimising those images and cleaning up the document's structure, then shows you the exact size reduction. If the first pass is not enough, you can re-compress harder to trade a little more quality for a smaller file.

How much can you compress a PDF?

It depends entirely on what is inside. A text-heavy PDF is already compact and may barely shrink, while a PDF full of high-resolution scanned pages or photos can often be reduced by half or more. The biggest wins come from documents where large images were embedded at far higher resolution than they need to be for screen or print at the intended size.

Does compressing reduce quality?

Light compression mostly removes waste and is visually lossless. Stronger compression downsamples images, which can soften detail if you push it far. For a balance, start with a moderate level, check that text stays sharp and images look acceptable, and only increase the strength if you specifically need a smaller file. Text itself stays crisp because it is stored as vectors, not pixels.

Common uses and privacy

Compressing a PDF is most useful for email attachment limits, faster uploads to portals and forms, and saving storage. Your file is processed securely and automatically deleted within an hour, so it is not kept after you download the result.