Compress PDF
Reduce PDF file size by adjusting the output quality.
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Shrink large PDFs down to a manageable size with a quality slider you control — processed entirely on your device, never uploaded.
Reduce PDF file size by adjusting the output quality.
No file selected
Large PDFs are usually big because of embedded images — scanned pages, photos, or graphics that were saved at a higher resolution than necessary. This tool renders each page of your PDF onto a canvas inside your browser, then re-encodes that page as a JPEG at the quality level you choose on the slider, and rebuilds a new, smaller PDF from those images using the pdf-lib library. All of that rendering and re-encoding happens locally using your device's own processor — your file is never sent to a server to be compressed remotely.
Because compression works by converting each page into an image, it's worth knowing the trade-off: a compressed page is no longer selectable, searchable text, it becomes a picture of the original page. This is standard behavior for image-based PDF compressors, and it's what makes the size reduction possible in the first place. If you need the text in your document to stay searchable after compressing, keep a copy of the original and only use the compressed version where a smaller file size matters more than text selection — for example, attaching a document to an email with a size limit.
Drag the quality slider lower for a smaller file (with softer image detail) or higher to preserve sharpness at the cost of file size. The tool shows you the new size next to the original so you can see exactly how much space you saved before downloading.
No installs, no accounts, and no waiting on server queues. Everything happens locally on your device.
Select a PDF and set the quality slider — lower means smaller file size, higher preserves more detail.
Each page is rendered and re-compressed as a JPEG directly in your browser using pdf.js and pdf-lib.
See the new size compared to the original, then download your compressed PDF.
The compression tool works by rendering each page as an image and re-encoding it at the quality level you choose. Lower settings produce smaller files but reduce sharpness, particularly around small text and fine lines, while higher settings preserve more detail at the cost of file size. Compressed pages are no longer selectable text; they become images of the original page.
For documents you mainly need to email or upload where sharpness doesn't matter much, 40–60% quality usually cuts file size dramatically while staying readable. For documents with fine print, photos, or diagrams you want to keep sharp, try 75–90% and compare the new file size against your target.
If your PDF is mostly plain text with no images, there often isn't much size to shrink — text-based PDFs are already compact. This tool is most effective on PDFs made up of scanned pages, photos, or high-resolution graphics.
There's no hard-coded limit, but because compression happens in your browser's memory, very large or very long PDFs may take longer or use more RAM depending on your device. For the smoothest experience with big files, use a desktop browser.
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