Free PDF Compressor Online
Reduce PDF file size by re-rendering pages at lower resolution. Ideal for email attachments and web uploads. No file upload — 100% private, powered by PDF.js.
Drop PDF here or browse
PDF files only · Max 100 MB
Good balance between size and quality
About the PDF Compressor
This tool compresses PDFs by rendering each page to a canvas at a reduced scale using PDF.js (Mozilla's open-source PDF renderer), then encoding each page as a JPEG image into a new PDF via pdf-lib. The result is a rasterised PDF — text will not be copy-selectable but the visual appearance is preserved.
Best for: Scanned documents, photo-heavy PDFs, reports with graphics. For text-only PDFs, compression savings may be modest.
How to Compress a PDF Online
Upload PDF
Click or drag-drop your PDF file (up to 100 MB).
Choose Level
Select Maximum (smallest file), Balanced (recommended), or Light (best quality).
Compress
Click "Compress PDF". Pages are rendered and re-encoded one by one.
Download
Download your compressed PDF. Size savings are shown before you download.
Frequently Asked Questions
No. This approach re-renders pages as images, so text becomes non-selectable in the output. For size reduction without losing text searchability, use the "Light" setting which preserves higher quality.
Image-heavy and scanned PDFs typically compress by 50–80%. Text-only PDFs may see 20–40% reduction. Maximum mode produces the smallest files at the cost of some visual quality.
Files up to 100 MB are supported. Very large PDFs (many pages at high resolution) may take longer on mobile devices. For best performance with large files, use a desktop browser.
No. All processing uses PDF.js and pdf-lib running locally in your browser. Your PDF never leaves your device.