Compress PDF Online

Compress PDFs privately in your browser

Large PDF files can be hard to email, slow to upload and awkward to store. This compress PDF tool reduces file size without sending your document anywhere. Your browser opens the PDF locally, renders each page to a canvas, saves that page as a JPG image and places the images into a fresh PDF. The finished file downloads from your device, so confidential scans, forms, receipts, contracts and personal paperwork stay under your control throughout the process.

The approach is intentionally practical. Many oversized PDFs are scanned documents where each page is already a large photo. Re-rendering those pages at a smaller scale and with controlled JPG quality can remove unnecessary pixels and reduce image data. Because the work happens in client-side JavaScript with pdfjs-dist and pdf-lib, there are no upload queues, account limits or server copies to worry about.

Best files and settings

Compression works best for scanned or image-heavy PDFs: photographed forms, signed pages, invoices, manuals and receipts. Start with the balanced settings, then lower JPG quality or scale if the output is still too large. A 1x scale is fastest and smallest, while 1.5x or 2x keeps more detail for fine print. Always open the compressed result and confirm that names, numbers and signatures remain readable before sharing it.

What changes during compression

This tool creates a rasterized copy. Text selection, links, form fields, bookmarks and layers from the original PDF are not preserved because each page becomes one JPG image in a new PDF. That trade-off is useful when file size matters more than editability, such as submitting a scanned packet to a portal or attaching records to an email. For mostly text-based PDFs, the original may already be smaller and sharper, so keep the source file as your archive copy.