So I made this simple tool, to allow you to get them as an SVG.
You can get them by chain ID...
<img src="https://icons.network/id/1" />
<img src="https://icons.network/id/10" />
Or by network slug (more readable, as long as it's not user input)...
<img src="https://icons.network/slug/mainnet" />
<img src="https://icons.network/slug/optimism" />
Relying on user input? You can add a fallback chain!
<img src="https://icons.network/id/0?fallback=10" />
<img src="https://icons.network/slug/this-doesnt-exist?fallback=ethereum" />
Have a chain you want to add? Contribute!