Compress PDF Online for Free
Reduce your PDF file size without losing quality. Fast, free, and fully private — your files are processed entirely in your browser.
Drag & drop files here or click to browse
Max file size: 100.0 MB
How to Compress a PDF to Reduce File Size
Upload your PDF
Drag and drop or click to select the PDF file you want to compress. Files up to 100 MB are supported.
Adjust the quality level
Use the quality slider to balance between smaller file size and visual quality. Lower quality means smaller files, higher quality preserves more detail.
Compress and download
Click "Compress" and download the optimized PDF. The tool removes unused data and optimizes the file structure without visible quality loss.
Why your PDF is so large — and what compression actually does
A 50 MB PDF is almost always the same story: someone scanned a document at 600 DPI when 200 DPI would have been plenty, or embedded full-resolution photos when 1500 pixels wide would have rendered identically on screen. The bytes are in the images, not the text. Compression reaches realistic sizes by re-encoding embedded images at sensible resolutions and JPEG quality, while leaving vector content, fonts, and text streams untouched.
Realistic outcomes: a scanned 30-page contract typically goes from 12–18 MB to 2–4 MB. A photo-heavy report goes from 40 MB to 6–10 MB. A text-only PDF (already compressed at export) may only shrink 5–10% — that is normal and means the file was already efficient. If you need to fit under a strict portal limit (10 MB IRS uploads, 5 MB DMV forms, 25 MB Gmail attachments), aim for one resolution tier below your current size; over-compressing scanned text can make small fonts blurry on print. For documents you will print, keep images at 300 DPI minimum.