Convert to WebP

WebP typically lands smaller than a JPEG of equivalent visual quality, and far smaller than a PNG for photographic content, while still supporting transparency. Every current browser supports it, which is why it's the sensible default for web imagery today.

Each conversion re-encodes at a high, visually-lossless setting, there's no slider to get wrong. If you need to trade quality for size deliberately, use the compressor instead.

WebP, AVIF, or leave it alone?

AVIF goes smaller still, but it costs real compute to encode well, so it's a paid-plan output rather than a free-tool one. WebP is the safe everyday choice. Images that are already small vector-like PNGs (icons, logos) often gain nothing, check the before/after size before you replace them.