How to Compress a PDF (Reduce File Size Without Losing Quality)
Email attachment limits and upload caps are usually 10–25 MB, and a photo-heavy PDF blows past that easily. Compressing a PDF removes wasted overhead and re-optimizes images so the file shrinks while staying readable. Here is how.
The tool
PDF Compressor
Step by step
- Open the compressorGo to the PDF Compressor in your browser — no install, no account.
- Add your PDFDrag the PDF in or click to select it.
- Choose quality (optional)Pick a balance of size vs. quality — Best quality, Balanced, or Smallest file.
- Compress and downloadRun it, then download the smaller PDF. Your file is deleted automatically within 24 hours.
Why is my PDF so large in the first place?
Almost always: images. Scanned pages and high-resolution photos store far more data than the screen or a printer actually needs. The compressor down-samples those images to a sensible resolution and re-encodes them, which is where the big savings come from.
Text and vector graphics barely add size, so a text-only PDF is already small — compression helps most on image- and scan-heavy files.
How to get the smallest possible file
Pick the Smallest file level for maximum compression: it squeezes the file as far as it safely can. Image-heavy and scanned PDFs shrink the most; a text-only PDF is already near its floor. Exact target sizes are not guaranteed, and there is always a trade-off between size and sharpness, so if the result looks too soft, try Balanced instead.
Frequently asked questions
Does compressing a PDF reduce quality?
It reduces image resolution where it will not be noticeable and keeps text crisp. You control the balance, and can choose a lighter setting to prioritize quality over size.
Is there a file size limit?
Uploads are capped at 20 MB on the free tier to keep processing fast. Kitolity Pro and Pro Max raise this to 100 MB.
Are my files stored?
No — files are processed securely and automatically deleted within 24 hours.