Compress PDF
Drop a PDF, pick a compression level and download a smaller file. Image-mode rasterises each page and re-encodes as JPEG for the biggest savings; lossless mode re-saves the original streams. Everything runs locally with pdf.js and pdf-lib — your file never leaves your device.
Compression runs entirely in your browser. Your PDF never leaves your device.
How to use this compress pdf
- Drop or pick a PDF. Page thumbnails render so you can see what's being compressed.
- Pick a quality preset — Maximum, High, Medium or Low compression — or drag the slider for a custom level.
- Choose Image mode for biggest savings (rasterises pages, text becomes non-selectable) or Lossless mode to keep original streams.
- Click Compress to process pages locally; track progress per page.
- Compare before vs after size, then download the smaller PDF.
Frequently asked questions
Why does the text in my contract become unsearchable after compression?
Image mode rasterises every page into a JPEG — the underlying text layer is discarded. That's where the big savings come from, but you lose Ctrl+F search, copy-paste and accessibility for screen readers. For contracts or anything you'll search later, use Lossless mode and accept smaller savings.
How much smaller will my PDF get?
Savings depend on the original. Scan-heavy or image-heavy PDFs often shrink 60-90% in Image mode. Text-only PDFs that are already optimised may barely shrink — try Lossless mode to be safe.
Why does text become non-selectable in Image mode?
Image mode rasterises each page to a JPEG and rebuilds the PDF around those images. That's how you get the biggest savings, but the underlying text is gone. Pick Lossless mode if you need selectable text.
Which quality preset should I pick?
Medium (70%) is a good default for everyday PDFs. High (50%) for emails and uploads. Maximum (30%) for archival scans where size matters more than detail. Low (85%) when you want only a modest reduction.