OrbConvert converts your image files online. Amongst many others, we support PNG, JPG, JPEG, WEBP, GIF, SVG and TIFF. You can use the options to control image resolution, quality and file size.
From
Portable PixMap
One of the Netpbm family: the simplest possible way to store a full-colour image, with no compression at all. Files are large, and it carries no transparency.
All PPM conversionsTo
JPEG 2000
A wavelet-based successor to JPEG that holds quality better at small sizes and can carry transparency. It never replaced JPEG on the web, so browser and desktop support is patchy.
All JP2 conversions