Convert to WebP

85% for 95% of use cases—produces imperceptible difference from JPG 95% but 30-40% smaller. Human eyes cannot distinguish 85% vs 95% WebP at typical screen viewing distances (under 2000px width). Use 90-95% only for critical hero images or portfolio work requiring pixel-perfect quality. Use 75-80% for thumbnails, backgrounds, or non-critical assets. Test by comparing side-by-side at actual display size—zoom to 100% and check detail preservation.

Yes for production sites targeting 100% users. WebP works in 96% of browsers (Chrome, Firefox, Edge, Safari 14+, Opera) but fails in IE11 and Safari 13 and older (4% market share, mostly legacy enterprise or outdated iOS). Use <picture> element: <source srcset='image.webp' type='image/webp'><img src='fallback.jpg'>. Modern browsers load WebP, old browsers load JPG. Without fallback, 4% of visitors see broken images. Check analytics to see if your 4% justifies implementation effort.

Depends on source format and content complexity. JPG photos→WebP: 25-35% at 85% quality. PNG photos→WebP: 50-75% (PNG terrible for photos). PNG graphics→WebP: 10-30% (PNG already efficient for flat colors). Simple content (gradients, solid colors) compresses 40%+. Complex content (foliage, fabric textures, noise) compresses 20-30%. Test 5-10 representative images before batch converting entire library. Diminishing returns above 90% quality.

Yes—WebP fully supports alpha channel transparency identical to PNG, but with 22-40% better compression. Converting transparent PNG logos/icons to WebP maintains transparency perfectly while reducing file size significantly. WebP transparency uses less browser memory and renders faster than PNG—dual benefit of smaller downloads and better client-side performance. Ideal for overlay graphics, watermarks, logos on colored backgrounds.

Convert everything over 5KB: photos, graphics, icons, backgrounds. Photos gain most (30-50% reduction), graphics gain less (10-20%), but every KB improves page speed. Exception: very small icons under 2-3KB may increase in size due to WebP header overhead (fixed 20-byte metadata cost). For favicons, tiny UI elements, keep PNG/SVG. For images 5KB+, always convert. Even 10% savings on 100KB image = 10KB × 1000 pageviews = 10MB bandwidth saved.

Yes, but you lose WebP's compression benefits. Converting WebP→JPG increases file size 30-40% (reverses savings). Use case: sharing images on platforms that don't support WebP (email clients, old forums, some social media). For web deployment, use <picture> fallback instead—serves WebP to modern browsers, JPG to old browsers automatically. Converting WebP→JPG→WebP compounds quality loss (double lossy compression)—always keep original high-quality sources.

WebP improves SEO indirectly through page speed. Google's Core Web Vitals include LCP (Largest Contentful Paint)—faster image loads directly boost search rankings. Sites converting to WebP report 15-30% LCP improvement, translating to ranking gains. Google Images supports WebP natively—no SEO penalty. Alt text, filename, and surrounding content matter more for image search ranking than format. Faster page = better user experience = higher rankings.