Why compress a PDF?
Large PDFs are hard to email (most providers cap attachments at 10–25 MB), slow to upload to forms and portals, and eat storage on shared drives. Compression reduces file size by re-encoding embedded images at a smaller resolution or lower quality.
What can actually be compressed?
- Image-heavy PDFs (scans, photos, presentations): Large gains, often 50–80% reduction.
- Text-only PDFs (contracts, reports): Small gains, the file is already compact.
Our tool always shows you the exact before/after file size so you know what you're getting before you download.
How to compress a PDF free: step by step
- Open the Compress PDF tool.
- Drop your PDF onto the upload zone.
- Choose a compression level:
- Light: Minor reduction, maximum visual quality.
- Medium: Best balance (recommended for most documents).
- Heavy: Maximum size reduction; images will look softer.
- Click Compress and wait for the progress bar.
- Review the before/after size comparison that appears.
- Download only if you are happy with the result.
No signup, no watermark
Many "free" PDF compressors add a watermark or limit files to 5 MB. This tool does neither, it runs entirely in your browser.
Tips for better compression
- Scanned PDFs: These compress the most because pages are large JPEGs or PNGs. Use Heavy compression for archive copies.
- Already compressed: If someone ran the PDF through iLovePDF or Smallpdf already, there is not much left to squeeze out.
- After compressing: If the result is still too large, try splitting the PDF and compressing each half.
What about text quality?
Text and vector graphics (shapes, charts drawn in software) are never re-encoded. They stay crisp at any zoom level. Only raster images embedded in the PDF are affected.