Compress PDF

The Compress PDF tool shrinks the file size of a PDF so it fits email attachments, upload forms, and storage limits without needing to remove pages. Compression runs entirely in your browser, keeping your document private.

Large PDFs are usually bloated by embedded images, duplicate fonts, or uncompressed streams. This tool re-encodes the document to reduce its footprint while keeping the text readable and the layout intact for most everyday documents.

PDF bloat typically comes from one of three sources: high-resolution images embedded at sizes far larger than the page needs, duplicate or subsetted fonts repeated across pages, and uncompressed content streams left over from the original export. This tool targets those areas directly, re-encoding images and streams so the file shrinks without altering the text layer or the page geometry.

Choose a compression level that matches your priority — a lighter pass keeps images near their original clarity for documents that will be printed, while a stronger pass aggressively downsamples images for files destined to be emailed or uploaded to a web form with a strict size cap. You can always run the tool a second time with a different setting and compare the two outputs side by side.

Compression runs locally in the browser using pdf-lib to read the document structure and a Canvas-based image re-encoder to process embedded raster graphics. When you start compression, the tool walks the PDF resource dictionary, identifies image objects, and re-renders each one through an off-screen canvas at a reduced resolution and JPEG quality matching the level you selected, then writes the smaller image back into the page.

Text and vector content are preserved untouched — only raster images and uncompressed streams are re-encoded — so selectable text stays selectable and vector line art keeps its sharpness at any zoom level. The result is a valid PDF that opens in every standard reader, with the page count, bookmarks, and links intact. Because the work happens on your device, there is no upload and no server-side copy of your document.

The degree of reduction depends entirely on the source: a text-only PDF may shrink only a few percent, while a scanned document full of high-resolution photos can shrink by 80 percent or more. If the first pass does not reach your target size, try a stronger level or pre-process the source images with the Compress Image tool before re-exporting the PDF. Password-protected files must be unlocked first.