Compress PDF
Reduce the size of a PDF so it fits email or upload limits. Choose how to compress it, and see the real size before and after. If the file does not get smaller, the tool says so instead of giving you a bigger file.
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How to use the Compress PDF
- Choose a PDF.
- Pick a method and a level. “Recompress photos” is the right choice for most documents.
- Select Compress PDF. Compare the sizes, then download the result or keep your original.
Example
brochure.pdf with several high-quality photos Method: Recompress photos, Balanced
brochure-compressed.pdf with the same text and layout, and lighter photos.
How much smaller depends entirely on the file. A PDF made mostly of text often shrinks very little.
About this tool
A PDF is usually large because of the images inside it. Recompress photos finds each embedded JPEG photo, re-saves it at the chosen quality and, at the Strong and Balanced levels, scales down very large ones. A photo is only replaced if the new version is at least 5% smaller. Text, fonts and drawings are not touched, so the document still reads and prints the same.
Lossless clean-up rewrites the file with compressed object streams, a more compact way to store the PDF’s internal structure. Convert pages to images is a last resort for scanned documents: every page becomes a single JPEG at the chosen resolution.
There is no hidden setting that shrinks every PDF by a fixed percentage. The result depends on how the file was made, which is why the tool always shows the actual numbers.
Known limitations
- “Recompress photos” only changes JPEG photos stored in RGB or grayscale. Lossless (PNG-style) images, CMYK images and transparency masks are left as they are.
- “Lossless clean-up” often saves only a few percent, and some files do not get smaller at all.
- “Convert pages to images” makes text unselectable and unsearchable, removes links and form fields, and can make files bigger for text-only documents.
- Compression runs on your device, so very large files are slower on phones. Files up to 200 MB.
Frequently asked questions
Which method should I choose?
Start with Recompress photos at Balanced. If the PDF is a scan and is still too large, try Convert pages to images. Use Lossless clean-up when you cannot accept any change in quality.
Why did my PDF not get smaller?
Its images may already be well compressed, stored in a lossless or CMYK format the tool leaves alone, or the file may be mostly text and fonts. In that case there is little to remove without changing the document.
Is my document uploaded?
No. All three methods run in your browser. Rendering pages for the image method uses PDF.js, which runs locally too.