PDF Compress
Compress PDF Online
Reduce the file size of your PDFs without compromising quality. Our advanced compression algorithm optimizes images and fonts to make your files smaller and easier to share.
- Smart Compression: Reduces size while maintaining quality
- Privacy Focused: Files are compressed locally, never uploaded
- Fast: Instant processing powered by WebAssembly
- Free: Unlimited compression, no watermarks
Why compress PDFs in your browser?
PDF compressors that upload your file to a server mean waiting on upload/download time and trusting that server with the document's content. This tool compresses using WebAssembly directly in your browser tab, so processing starts instantly and the file never leaves your device — worth it for anything from a large scanned contract to a simple file-size limit on an email attachment.
Comparison
Comparison
- Speed: Faster than most online PDF compressors due to local processing
- Security: 100% private - files never leave your device
- Quality: High-fidelity compression settings available
How to Use
- Select your PDF file
- Choose a compression level (Low, Medium, High)
- Wait for the compression to finish
- Download your smaller PDF file
💡 Pro Tips
- Start with "Medium" — it usually gives a large size reduction with no visible quality difference for typical documents.
- Use "High" compression when you need to hit a strict size limit (like an email attachment cap), accepting some visible image quality loss.
Glossary
- Lossless Compression
- Reducing file size without removing any data, allowing the original file to be perfectly reconstructed.
- Lossy Compression
- Reducing file size by permanently removing some data (usually imperceptible to the human eye) to achieve smaller sizes.
- Image Downsampling
- Reducing the resolution of embedded images within a PDF, one of the main techniques used to shrink file size.
- Font Subsetting
- Embedding only the specific characters actually used from a font, rather than the entire font file, to reduce PDF size.