Choose based on the image, not the extension
Photographs tolerate lossy compression well, while screenshots, diagrams, text, and flat-color graphics often reveal compression artifacts quickly. Transparency and the destination application can narrow the choice before file size is considered.
Keep the best available source
Repeated lossy conversions discard more information. Keep the original camera file or lossless master, then export JPG or WebP variants from that source instead of converting a compressed download back and forth.
Use transparency intentionally
PNG and WebP can preserve transparency; JPG cannot. If the image has no transparent pixels, an opaque export may be smaller and easier to use in older software. Check edge quality against both light and dark backgrounds.
Measure the result in its real context
Compare dimensions, file size, visible detail, color, and compatibility in the actual browser, CMS, or application. A smaller file is not a win if text becomes fuzzy, gradients band, or the target rejects the format.
Quick image format comparison
| Format | Strong fit | Main tradeoff |
|---|---|---|
| WebP | Web photos and graphics with modern compression | Some older workflows and editors may reject it |
| PNG | Screenshots, line art, lossless detail, transparency | Large files for photographic content |
| JPG | Photographs and broad software compatibility | Lossy artifacts and no transparency |