Compress PDF

Why compress a PDF

Email services, job portals and government forms often refuse attachments over a few megabytes, and the PDFs that break those limits are nearly always full of images: scanned pages, photos of receipts, a brochure with high-resolution pictures. This tool finds the JPEG photos and scans inside the PDF, scales down those that have more pixels than the page needs and saves them again at a lower quality, while text, fonts, links, bookmarks and form fields stay as they are. You choose how far to go, and the result shows the size before and after. If a setting would not make the file smaller, you get no download and a note instead, so you never end up with a bigger file. Nothing is uploaded: the work happens in your browser.

How to compress a PDF

1. Drop your PDF in the box, or click to choose it.
2. Choose a method and an image quality. The recommended method keeps text selectable.
3. Click Compress PDF, compare the sizes and download the smaller file.

What changes when you convert

What each method does

"Shrink images, keep text" re-encodes JPEG images at about 96, 150 or 200 DPI for an A4 or Letter page, and also does the lossless clean-up. "Lossless clean-up only" just compresses parts that are stored without compression, packs the file structure into compressed object streams and drops objects nothing uses; the pages look exactly the same. "Pages to images" redraws each page as a JPEG, which gives the smallest file for scans but makes the text unselectable and removes links and form fields.

Which PDFs shrink, and which don't

Scans and photo-heavy PDFs often get several times smaller. PDFs exported from Word or a web page are mostly text and fonts, which are already compressed, so expect a small saving or none. Embedded fonts are kept whole, because removing them would change how the text looks.

Images that are left alone

Only JPEG images in RGB or greyscale are re-encoded. Images stored without loss (such as screenshots), CMYK images in print-ready files, images with masks and black-and-white scans in fax compression are kept as they are, and so is any image that would get less than 10 % smaller.

Turning pages into images

This flattens everything: text becomes pixels, so you can no longer search, select or copy it, and links, bookmarks and fillable fields are gone. For a document that is mostly typed text, the image version is usually larger, and you will be told so. Use it for scans and for PDFs that simply have to be small and readable.

Signatures and passwords

Any change to the file breaks a digital signature, so compress before signing. Encrypted PDFs, including those that open without a password but restrict editing, cannot be compressed here.