eBook File Size Compressor — Free Online Tool
Shrink large EPUB and CBZ files without losing reading clarity. Recompresses oversized JPEG/PNG images, strips bloated metadata, and repacks with maximum DEFLATE compression.
Interactive Tool Workspace Ready
Upload your file to begin processing locally on your device with WebAssembly security.
How to Use eBook File Size Compressor Online
- Step 1: Upload Heavy eBook — Select your oversized .epub or .cbz file.
- Step 2: Choose Optimization Level — Select Low, Medium, or High image compression.
- Step 3: Download Compressed eBook — Enjoy reduced file size ready for email or e-readers.
Why Use PDFly XO for eBook File Size Compressor?
- 100% Client-Side Privacy: All file processing is performed locally in your web browser. Your private documents are never uploaded to any remote server.
- Zero Wait Time: Local WebAssembly execution ensures near-instant document processing without file size upload latency.
- Free & Unlimited: Complete access with no subscriptions, watermarks, or hidden paywalls.
Frequently Asked Questions
- Will compressing my EPUB ruin text quality?
- No! Text, fonts, and XHTML structure remain 100% lossless. Only embedded photos and raster illustrations are optimized.
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