How do I make PNGs responsive?

Q: How do I make PNGs responsive?

Use <code>srcset</code> + <code>sizes</code>: <code>&lt;img srcset="img-300.png 300w, img-900.png 900w" sizes="(max-width:600px) 300px, 900px"&gt;</code>. The browser picks the right size.

Use srcset + sizes: <img srcset="img-300.png 300w, img-900.png 900w" sizes="(max-width:600px) 300px, 900px">. The browser picks the right size.