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Most widely used lossy format. Excellent for photographs with millions of colors.
Lossless format with transparency. Perfect for graphics with sharp edges.
Modern format with superior compression. 25-35% smaller than JPEG.
Next-generation format with best compression. 50% smaller than JPEG.
The compression ratio shows how much smaller the compressed file is compared to the original. A ratio of 5:1 means the compressed file is 1/5th the size of the original.
Reduces file size by removing some image data. Quality decreases but file size dramatically shrinks.
Reduces file size without any quality loss. Original image can be perfectly reconstructed.
Nearly identical to original. Minimal compression.
Recommended sweet spot. Great quality, good compression.
Good for web. Visible on close inspection.
Noticeable artifacts. Use for thumbnails.
Heavy artifacts. Avoid unless necessary.
For web images, aim for 3:1 to 5:1 compression ratio. This typically means JPEG at 80-85% quality or WebP at 75-80%. This provides good visual quality while significantly reducing load times. Higher ratios (10:1+) are possible with modern formats like AVIF but may show artifacts on detailed inspection.
Use WebP if you're building a modern website and can provide fallbacks. WebP offers 25-35% better compression than JPEG at equivalent quality levels. However, use JPEG if you need universal compatibility (email attachments, older systems) or don't want to implement fallback mechanisms. The best approach is to use both with the picture element.
Use PNG for: logos, icons, graphics with text, images with transparency, and screenshots with sharp edges. PNG is lossless, so it preserves crisp edges and text perfectly. Don't use PNG for photographs - it will result in much larger files than JPEG with no visible benefit. For photos, use JPEG or WebP.
Yes, AVIF typically offers 20-30% better compression than WebP at the same quality level, making it about 50% better than JPEG. However, AVIF has slower encoding times and limited browser support (not supported in Safari until 2023). Use AVIF for cutting-edge sites with fallbacks to WebP and JPEG. For wider compatibility, WebP is currently the better choice.
Re-compressing lossy formats (JPEG) causes quality degradation with diminishing returns. If an image is already JPEG at 80% quality, re-compressing to 60% won't save much space but will significantly reduce quality. Instead, always work from the highest quality source and compress once to your target. Converting to a more efficient format (JPEG → WebP) is beneficial.
Use the HTML picture element: <picture><source srcset="image.webp" type="image/webp"><img src="image.jpg"></picture>. Browsers that support WebP will use it; others fall back to JPEG. This gives you the best of both worlds - modern compression for capable browsers and universal compatibility.
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