Our PDF compressor uses multiple techniques: 1) Optimizing image quality and resolution, 2) Removing redundant fonts and metadata, 3) Compressing text and vector graphics, 4) Applying advanced ZIP compression to the PDF structure. You can choose between three compression levels (low, medium, high) depending on your quality needs.

The free version supports files up to 50MB. Premium accounts can compress files up to 500MB. For larger files, we recommend: 1) Splitting the PDF into smaller parts, 2) Using our desktop application, 3) Contacting us for enterprise solutions. Most standard PDFs (under 50 pages) compress well within the free limit.

With our smart compression: 1) Text remains sharp at all levels, 2) Images show minimal quality loss at medium compression, 3) High compression may reduce image clarity (best for screen viewing). We provide a preview feature so you can check quality before downloading. For archival purposes, use "lossless" compression mode.

Lossy compression reduces file size by permanently removing some data (mainly from images) - best for web use. Lossless compression preserves all original data through efficient encoding - ideal for printing or archival. Our tool automatically recommends the best method based on your PDF content.

Yes! Our premium version offers: 1) Selective page compression, 2) Different settings per page range, 3) Option to extract then reinsert pages after compression. For example, you can compress image-heavy pages aggressively while keeping text pages at higher quality. The free version compresses the entire document uniformly.

For scanned PDFs: 1) Use our "OCR + Compress" option to make text searchable, 2) Choose "Document" mode rather than "Image" mode, 3) Set DPI between 150-300 (lower for smaller files), 4) Enable "Smart Compression" to detect text vs images. Scanned documents often compress 80-90% without significant quality loss.

Absolutely. We use: 1) 256-bit SSL encryption during transfer, 2) Automatic file deletion after 2 hours, 3) No human access to your documents, 4) Option to process files locally in your browser. For highly sensitive documents, use our offline desktop version that processes files without internet upload.

By default, we preserve: 1) Password protection, 2) Digital signatures, 3) Form fields. However, you can optionally: 1) Remove metadata (author, creator info), 2) Strip annotations, 3) Flatten form data, 4) Delete embedded files. These options are available in the "Advanced Settings" before compression.

Yes! We offer three options: 1) Browser-based processing (no upload) in Chrome/Firefox, 2) Downloadable desktop application (Windows/Mac), 3) Command-line tools for developers. The browser version handles files up to 20MB locally, while the desktop app has no size restrictions.

This rare occurrence can happen when: 1) Converting from optimized JPEG2000 to standard JPEG, 2) Adding transparency to images, 3) Embedding fonts that were previously referenced, 4) The PDF was already highly compressed. Try using a lower quality setting or different compression method if this occurs.

For blurry output: 1) Increase the image quality setting, 2) Try "Lossless" compression mode, 3) Select "Preserve Text Quality" option, 4) For scanned documents, use "Text Enhancement" filter, 5) Avoid extreme downsampling (keep DPI above 200 for print). Our preview feature helps catch these issues before finalizing.

Compression may fail with: 1) Password-protected files (unlock first), 2) Corrupted PDF structure, 3) Certain embedded 3D/content, 4) Extremely large files. Try: repairing the PDF first, converting to images then back to PDF, or splitting into smaller files. Our support team can help with problematic files.