Use the HTML '<'picture> element to serve modern formats with automatic fallback - browsers pick the first format they support:
<picture> <!-- Best compression (AVIF) — ~95% browser support --> <source srcset="image.avif" type="image/avif" /> <!-- Excellent fallback (WebP) — ~97% browser support --> <source srcset="image.webp" type="image/webp" /> <!-- Universal fallback (JPEG) — 100% support --> <img src="image.jpg" alt="Product photo" width="800" height="600" /> </picture>
Search or browse the format comparison and match its capabilities to your image. Start with the highest quality source, resize it to the display dimensions, then compare encoded results at the quality you need. Use PNG for a raster source that needs transparency and JPEG when a photographic image can accept lossy encoding. Keep SVG for suitable vector artwork instead of assuming every format is interchangeable.
The picture example below lets a browser select a supported source with a JPEG fallback. It illustrates website markup rather than a converter output. This site's converter exports JPEG, PNG, and supported WebP; other reference formats are not promised exports. Serve responsive sizes and lazy load below the fold images when appropriate. Keep the original source rather than repeatedly recompressing an already compressed file.
<picture>
<source srcset="image.avif" type="image/avif">
<source srcset="image.webp" type="image/webp">
<img src="image.jpg" alt="Description" loading="lazy">
</picture>
AVIF offers the best compression (20-50% better than WebP, 50-80% better than JPEG) but has slightly less browser support than WebP. WebP is supported by all modern browsers (95%+ globally). Use the '<'picture> element with AVIF as the primary source, WebP as fallback, and JPEG/PNG as the final fallback. This gives optimal compression with universal compatibility.
Use PNG when you need: (1) transparency/alpha channel, (2) lossless quality for screenshots or text-heavy images, (3) images with sharp edges like logos or diagrams. Use JPEG for photos where some color data can be discarded. PNG files are significantly larger than JPEG for photographs but smaller for simple graphics with flat colors.
SVG is ideal for logos, icons, and illustrations: infinitely scalable without quality loss, tiny file sizes for simple graphics, can be styled with CSS, and animated. For raster icons, use WebP or PNG with transparency. Avoid JPEG for icons and logos — the lossy compression creates visible artifacts around sharp edges.
Independent studies show AVIF reduces file sizes by 50-80% compared to JPEG at equivalent visual quality. For a typical 300KB JPEG product photo, AVIF might achieve same quality at 60-150KB. AVIF uses AV1 compression and supports HDR, wide color gamut, and both lossy and lossless modes. The trade-off is slower encoding time compared to JPEG/WebP.