How to Compress a PDF Without Losing Quality

Compressing a PDF without losing quality means different things depending on what is making your file big. If it is bloated by inefficient structure — the usual cause for text-and-vector documents — you can shrink it losslessly, with zero visible change. If it is heavy because it is full of high-resolution scans or photos, real savings require re-encoding those images, which is a deliberate trade-off.

PdfWill's compress tool exposes this directly. The low setting is lossless: it recompresses the file's streams with qpdf, so every character stays sharp and all the text remains selectable — you just get a leaner file. Choose this when your PDF is mostly text and you refuse to give up any quality.

The medium and high settings are for image-heavy PDFs. They re-render each page and re-encode it as a downsampled JPEG, which can cut a scanned document dramatically in size. The cost is that the page becomes an image, so its text is no longer selectable. That is the right choice for a folder of scans headed to email, and the wrong choice for a contract you will want to search later.

A smart habit is to try the lossless setting first and check the result. If it is small enough, you have lost nothing. Only step up to image compression if you still need more, and only when selectable text is not essential for that particular file.

Everything runs locally, and PdfWill never hands you a file that got bigger — if compression would not help, it simply returns the original. If a document is large mainly because it bundles many things, splitting it or converting color scans to grayscale can shrink it further without touching resolution.