How to Compress a PDF to Reduce File Size

Email attachment limits and upload forms love to reject big PDFs. Most oversized PDFs are large because of high-resolution imagesinside them — scanned pages, photos, or exported designs. Here's how to shrink one down.

Compress a PDF

Use the Compress PDF tool:

1. Open Compress PDF and choose your file.
2. Pick a quality/resolution level (lower = smaller file).
3. Compress and download — you'll see the before/after size.

It works especially well on scanned or image-heavy PDFs, which are usually the biggest offenders.

Pick the right quality

• Medium is a good default — big size savings, still readable.
• Low for the smallest file when it's just for reference or email.
• High when print quality matters and you only need a modest reduction.

Prevent big PDFs in the first place

If you're building a PDF from images, compress the images before you combine them with Compress Image, then assemble them with Images to PDF. Smaller inputs mean a smaller PDF from the start.

FAQ

Will compressing ruin the quality?

There's a trade-off, but at medium quality the difference is usually hard to notice while the file gets much smaller.

Is my file uploaded?

Your document is processed to compress it and then discarded — it isn't stored.