Preferred Image Format
PNG: Produces better quality images but comes with larger file size. Usually better for graphics with fewer than 16 colors. PNGs are also used for images with clear backgrounds and are good for vector images.
JPEG: May lose image quality, but can adjust the quality level to find a good balance. Usually better for photographs.
Other formats allowed: BMP, GIF, WebP, SVG
...
100 KB (100,000 bytes) is the recommended image size for the web
Larger image sizes can slow down the load time of the page which negatively impacts SEO SEO
If the page takes longer to load, a user is more likely to bounce and go to a competitor site that does not take long to load.
Image File Name Customization
...
Create a good URL structure for your images as Google uses the URL path as well as the file name to help it understand your images.
Image Structured Data
If you use structure data, Google images can display your web images as rich results which give users relevant information about your web page and can drive better-targeted traffic to your site. Google images supports structured data for:
Additional Resources
...