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MyPDFToolbox

Compress PDF

Client-side

Reduce the size of a PDF by recompressing its pages in your browser.

Runs 100% in your browser · Options are saved only in this browser, if you allow it — never your files

Drag and drop your PDF here

or

Up to 100 MB per file · Your files never leave your device.

Compression level

Pages are converted to compressed images: the visual look is kept, but text will no longer be selectable or searchable. Best for scans and image-heavy documents.

What does Compress PDF do?

Compress PDF makes large documents smaller so they fit e-mail attachment limits, upload faster to web forms and take less space on your phone or in the cloud. It works best on the files that are usually the heaviest: scanned documents, photo albums, brochures and presentations full of images, where reductions of 50–90% are common.

How it works – and what to expect

Each page is drawn by PDF.js at the resolution you choose and saved as a JPEG image, then pdf-lib builds a new PDF from those images, keeping the page sizes and the document title and author. This is very effective for scans and pictures. The trade-off is that the text becomes part of the image: it still looks the same, but it can no longer be selected, copied or searched, and links stop working. The page says so clearly before you start, and the original file on your device is never modified.

If a document is mostly text created by a word processor, it is usually already compact, and converting it to images may not make it smaller. In that case the tool tells you and you can simply keep your original.

Private by design

The whole process runs in your browser. Your document is not uploaded to any server, which is reassuring when the large file is a scanned passport, a medical record or a signed contract.

How to compress a PDF

  1. Drop your PDF onto the drop zone or click Choose file.
  2. Choose a level:
    • Strong (72 ppi): the smallest files, fine for reading on screen.
    • Balanced (110 ppi): a good compromise for sharing by e-mail.
    • Light (150 ppi): better quality for printing, with a smaller reduction.
  3. Click Compress PDF. Progress is shown page by page and you can stop at any time.
  4. Compare the original and new sizes, check the preview of the first page and download the result.

Frequently asked questions

How much smaller will my file be?

It depends on the content. A 20 MB scan typically drops to 2–5 MB at the balanced level. Documents that are already optimized may not shrink at all.

Can I keep the text selectable?

Not with this method. If you need searchable text, keep the original, or compress only the image-heavy part after separating it with Split PDF.

What are the limits?

Up to 100 MB and 500 pages. Large documents need some memory, so phones may be slower than computers.