About Compress PDF
Compress PDF makes a PDF smaller so it fits through email limits, government portals and job application forms. The tool finds the photos and scans inside your PDF, re-encodes them at a lower size, and leaves the text and vector graphics alone.
That approach keeps text crisp and selectable, which matters for contracts, CVs and reports that someone will search or copy from. A 25 MB brochure full of photos often drops below 3 MB on the Balanced setting.
For scanned documents where every page is one big picture, the Maximum compression option renders each page as a JPEG and rebuilds the file. That gives the smallest result, at the cost of selectable text.
How to use Compress PDF
- Open the PDF you want to shrink.
- Pick a level: Light for print quality, Balanced for email, Strong for the smallest size.
- Tick Maximum compression only for scans or when the other levels aren't enough.
- Click Compress PDF and wait for the progress bar.
- Check the size reduction shown in the result, then download.
Text stays text
Only embedded images get recompressed. Fonts, text and vector drawings keep full quality.
Three levels
Choose how much image quality you trade for size, from near-original to email-friendly.
Never bigger
If compression can't beat the original, you get the original back instead of a larger file.
No size cap
Compress 100 MB scans without upload limits or waiting in a queue.
Why some PDFs shrink a lot and others barely move
File size in a PDF comes from three places: images, fonts and page content. Photos and scans usually account for more than 90 percent of a large PDF. Text and drawings take little space, because a page of text needs only a few kilobytes of instructions plus a font that the whole document shares.
This tool goes after the images. It decodes each JPEG or raw image in the file, scales it down if it has far more pixels than any screen or printer needs, and saves it again as a JPEG at the quality your level sets. Light keeps up to 2400 pixels on the long side at 82 percent quality. Balanced keeps 1600 pixels at 68 percent. Strong keeps 1100 pixels at 50 percent. The tool only swaps an image when the new version comes out at least 5 percent smaller.
A PDF exported from Word or a text-only report contains few images, so compression saves little. The tool still rewrites the file structure with compressed object streams, which trims some overhead, but don't expect a 5 MB text PDF to fall to 500 KB. Most of its weight sits in embedded fonts, and removing them would break the text.
Scanned documents behave differently again. Each page is one large image, often stored in a format that JPEG can't improve on without visible loss. For those, Maximum compression renders the page at a fixed resolution and stores it as a JPEG. A 40-page scan at 300 DPI often drops from 60 MB to 5 MB this way. The text was never selectable in a scan, so you lose nothing on that front.
Images with transparency, CMYK images from print workflows and special image masks stay untouched. Recompressing them would change colors or break transparency, and the tool skips them to keep the document looking the same.
Tips for better results
- Start with Balanced. Move to Strong only if the file is still too large.
- Compress once, at the end. Compressing an already compressed file again adds blur and saves little.
- Merge first, compress second. Compressing the merged file avoids repeating shared resources.
- For black-and-white printing, Grayscale PDF often removes another 20 to 40 percent.
- Check photos at 100 percent zoom after Strong compression if the document goes to print.
Questions and answers
Will compression make my text blurry?
No. The standard levels touch only images. Text and vector graphics stay as they were. Only the Maximum compression option turns pages into images.
Why did my file get only a little smaller?
Your PDF contains few images, or its images are already well compressed. Text-heavy files have little to gain.
Is there a file size limit?
No fixed limit. Very large files need more memory, so a laptop handles them better than an old phone.
Are my files uploaded?
No. Compression runs in your browser. Your PDF stays on your device.
Which level should I use for email?
Balanced. It keeps photos clear on screen and usually brings documents under common 10 MB and 20 MB attachment limits.
Can I compress a password-protected PDF?
Unlock it first with Unlock PDF, compress it, then protect it again with Protect PDF if needed.