Compress PDF
BetaReduce PDF file size by rewriting its structure and downsampling oversized images. You get the original back if nothing shrinks.
How to compress a PDF
- Choose a PDF.
- Pick Gentle, Balanced or Maximum.
- Press Compress PDF.
- Check how much smaller the file is, then download it. If it did not shrink, the result says so.
Options
- Gentle
- Rewrites the file structure only, packing objects and rebuilding the cross-reference table. Images are not touched. Gains are largest on files saved many times or exported for fast web view.
- Balanced
- Also re-encodes images shown at more than 150 pixels per inch on the page down to 150, as JPEG at 82% quality. Suits email and on-screen reading.
- Maximum
- Re-encodes images above 110 pixels per inch down to 110, at 72% quality. Gives the smallest file; check fine detail and small text inside images.
What you get
- One PDF with the same pages in the same order and the same file name.
- Text, vector graphics and fonts are not changed. Only image data and file structure are.
- Each image is replaced only if its new version is smaller. If the whole file does not shrink, Deckle keeps the original and says nothing was compressed.
- Greyscale images that are re-encoded become RGB. The document's Producer field can change.
Limits
- There is no target size. You pick a level and get whatever saving it produces.
- Only JPEG and plain Flate images in RGB or greyscale are re-encoded. CMYK, ICC-tagged, indexed and masked images, and images inside form XObjects, are left exactly as they are.
- Text-only and vector PDFs usually shrink little, because they have no images to downsample.
- A password-protected PDF must be unlocked first. A PDF with permission restrictions loses them in the compressed copy.
- Fonts are not subset or removed.
Check the result
After compression Deckle checks that the PDF opens, has the same page count and keeps its text. It also compares how the pages look and warns if they differ beyond a set threshold. Zoom into photos and small print in the download before replacing the original.
Questions
How much will my PDF shrink?
It depends on the content. Scans and photo-heavy PDFs with high-resolution images shrink most with Balanced or Maximum. Text-only files may shrink only a little, or not at all.
Can I compress a PDF to a specific size, such as 1 MB?
No. There is no target-size setting. Try Balanced first, then Maximum if the file is still too large.
Will compression make text blurry?
Real text is never re-encoded, so it stays sharp. Text that is part of an image, such as in a scan, can soften at Maximum.
What happens if the compressed file is bigger?
Deckle keeps the original byte for byte and tells you nothing was compressed. You never get a larger file back.
Is my PDF uploaded to compress it?
No. Compression runs in your browser and the file stays on your device.
Can I compress a password-protected PDF?
Not while it is locked. Use Unlock PDF first, then compress the unlocked copy.
Does compression remove bookmarks, links or form fields?
No. The document is rewritten with the same objects, so bookmarks, links and form fields stay. Only oversized images and the file's internal layout change.
Which level should I pick for email?
Balanced. It keeps images at 150 pixels per inch, which reads well on screen and prints acceptably. Use Maximum when an upload portal sets a hard size cap.