JPG for familiar photo workflows
JPEG is one of the most widely accepted image formats. It is designed for photographic content and offers adjustable lossy compression, which can make detailed photos reasonably small. JPEG does not preserve transparency. When you convert a transparent logo into JPEG, you must choose a background color for the empty areas.
PNG for crisp graphics and transparency
PNG is well suited to interface artwork, screenshots with sharp elements, illustrations, and assets requiring reliable transparency. It supports lossless image storage, but the file size can be substantial for photographs. Exporting PNG from a previously compressed JPEG does not restore detail or turn that image into a true untouched master.
WebP for efficient web publishing
WebP supports transparency and both lossy and lossless encoding. It is a practical choice for many website images, but the results depend on how the source is encoded. Always test the exported picture: a format label by itself does not guarantee a particular file-size reduction. CompIMG uses the current browser encoder, which may produce somewhat different results across devices.
AVIF for modern delivery
AVIF can achieve impressive compression efficiency and supports transparency. However, the ability to decode or encode AVIF depends on the browser and the specific environment. If your current browser cannot encode AVIF, choose another format instead of changing only the filename extension. For broad compatibility with external tools, maintaining a JPEG or PNG fallback remains useful.
A quick decision guide
Use JPEG for everyday photos that must work almost everywhere. Use PNG for graphics requiring crisp edges and transparent backgrounds. Try WebP for efficient modern image delivery. Consider AVIF when your publishing system and audience support it. When unsure, test the output, compare bytes and judge visible quality.