このガイドの本文は英語です。
Choosing the right image container format is just as important as tuning compression quality. Here is how the three dominant web image formats compare in 2026:
1. Format Breakdown
- JPEG (.jpg): Best for photographs, realistic lighting, and complex color gradients without transparency. Universally supported across every legacy email client and browser.
- PNG (.png): Ideal for UI graphics, logos, line art, and screenshots requiring crisp text or alpha transparency. Quantizing PNGs in LionPress cuts file size by 50%–75%.
- WebP (.webp): Combines the best of both worlds—supporting both lossy photographic compression and lossless alpha transparency at 25%–35% smaller file sizes than JPEG and PNG, with 98%+ global browser support.
2. Batch Format Conversion in One Click
With LionPress, you can drag and drop a mixed folder of PNGs and JPEGs, select Convert to WebP (Smallest) in the toolbar, and download a single .ZIP archive ready for production deployment.