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
Flexible Image Transport System
The standard format of astronomy, carrying scientific data alongside the image. Files are typically far larger than the same picture as PNG.
All FITS conversionsTo
Tagged Image File Format
Built for print and archiving: lossless, and able to carry multiple pages. Files are large and browsers will not display it, so it is not a format to publish online.
All TIFF conversions