How to compress a PDF to 100 KB
Shrink a large PDF to around 100 KB for email and uploads — free and online.
Large PDFs bounce back from email and fail upload limits. Compressing re-optimises the images inside so the file gets much smaller while staying readable.
Step by step
Open the Compress PDF tool and drop in your file.
Choose a compression level — pick 'Strong' for the smallest size.
Click Compress, then check the new size and repeat at a higher level if needed.
How small can it go?
File size depends mostly on the images inside — scanned documents shrink the most. If 'Strong' still isn't small enough, the pages are image-heavy; try splitting the document or reducing the source scan resolution.
Frequently asked questions
Will compressing reduce quality?
Stronger compression rasterises pages, so text becomes part of the image. Use 'Light' to keep more fidelity, 'Strong' for the smallest file.
Is it private?
Yes — compression happens in your browser; nothing is uploaded.