Lossy vs. Lossless Compression
Lossy compression — used by JPEG and WebP in quality mode — permanently discards image data that the human eye is unlikely to notice. The compression algorithm groups similar pixel colors and rounds them to fewer values, reducing the data needed to represent the image. At quality settings above 70%, the result is visually indistinguishable from the original for photographs.
Lossless compression — used by PNG — reorganizes pixel data more efficiently without discarding any information. The original image can be reconstructed exactly. Lossless is ideal for screenshots, logos, and graphics with flat colors or sharp edges, where lossy artifacts would be visible.
JPEG vs. PNG vs. WebP: Which Format to Use
JPEG is best for photographs and images with smooth color gradients. It achieves small file sizes through aggressive lossy compression. JPEG does not support transparency. Use JPEG for product photos, hero images, and any photo-realistic content.
PNG is best for graphics, logos, screenshots, and images that require transparency (alpha channel). Because it is lossless, PNG files are larger than JPEG for photos. PNG-24 supports full color with transparency; PNG-8 limits to 256 colors for very small flat-color images.
WebP is a modern format developed by Google that supports both lossy and lossless encoding with better compression efficiency than JPEG or PNG. WebP is supported in all modern browsers (Chrome, Firefox, Safari 14+, Edge). Use WebP as a default output when broad compatibility and small file size are both priorities.
When to Use Each Preset
Balanced — JPEG at 82% quality, no resize. The right default for most uploads: photos remain sharp at normal sizes while file size drops significantly. Use for blog posts, product listings, and general web publishing.
Smallest — WebP at 65% quality, capped at 1920px wide. Maximizes compression for email attachments, slow network delivery, or mobile-first pages where byte count matters more than pixel-perfect quality.
Web — JPEG at 80% quality, capped at 2048px wide. A safe choice for full-width hero images and gallery photos where the display size is known and maximum sharpness at that size is the goal.
Social — JPEG at 82% quality, capped at 1080×1080px. Matches the display dimensions of most social media platforms, preventing platforms from re-compressing your image a second time.
Custom — Full manual control over format, quality, and maximum dimensions. Use when the presets do not match your specific requirements.