Most PDF files are bigger than they need to be. A 10 MB scan of a two-page form can drop to 800 KB with no visible difference. The trick is understanding what's inside the file and which parts can shrink safely.
Why PDFs get bloated
Scanned documents embed images at 300 DPI or higher because scanners default to print resolution. Screens only need 96 DPI, so most of that data goes unused. Documents exported from Word, InDesign, or PowerPoint carry embedded fonts, color profiles, and thumbnail previews you'll never open. Some PDF print drivers include print settings in the file header.
None of this is visible when you read the document. It just makes the file heavier.
The "quality" question, answered
Text in a PDF is vector data, not pixels. Compression doesn't blur it. The only thing that can visibly degrade is embedded images. At 144 DPI, photos still look sharp on any monitor and print acceptably on a home printer. At 72 DPI, zoomed-in images start to look soft.
For a lease agreement, tax form, or invoice, 144 DPI is fine. For a photo portfolio, stay above 200 DPI.
How to compress your PDF on EvrythingPDF
- Go to the Compress PDF tool.
- Drag your file onto the upload area or click to browse.
- Choose a compression level. "Medium" handles most files well. Use "High" for scanned documents.
- Click Compress. Your browser processes the file locally — nothing uploads to a server.
- Download the compressed file. The tool shows you both file sizes so you can compare.
Compress your PDF now — free, no account, no watermarks.
Compress PDF FreeWhen compression won't help much
A PDF that's already optimized won't shrink significantly. If your file is mostly vector text with no images, compression might save 5 to 10 percent. That's still worth doing before an email attachment, but it won't turn a 4 MB file into 400 KB.
Files where compression pays off most:
- Scanned documents (often 60 to 80 percent reduction)
- Exports from design software like Canva, Illustrator, or InDesign
- Presentations saved as PDF from PowerPoint or Google Slides
- PDFs with embedded photos or diagrams
Compress and then merge, or merge first?
Compress each file first, then merge. You get a smaller final document and the merge runs faster. If you merge bloated files and then compress, the compressor has to work through one large file instead of several smaller ones. Either way works, but the compress-first approach tends to produce a smaller result.
After compressing: check the output
Open the compressed file and flip through every page. Zoom into any photos or diagrams to check sharpness. Confirm that signatures, stamps, and fine print are still legible. If anything looks off, run the compression again at a lower setting.
Most people never need to go back. The default medium setting in EvrythingPDF's tool hits a good balance for the files most people send day to day.