1
EWWW Image Optimizer Included
Converts to the best format, e.g. PNG to JPG or GIF to PNG.
94feature score
WordPress Image Optimization Plugins with PNG to JPG conversion
Converts photos saved as PNG to smaller JPGs. 3 of the 8 plugins we track include it.
2
Smush Included
Converts non-transparent PNGs to JPEG; no Pro label in the docs.
92feature score
3
ShortPixel Image Optimizer Included
Optional automatic PNG-to-JPG conversion when the result is smaller.
90feature score