HomeBrew, which calls itself The missing package manager for macOS is in my opinion essential for any macOS user. If you are missing a command or utility, chances are that HomeBrew has you covered.
Once you have HomeBrew installed, you’re pretty much ready to go by running the following command in Terminal:
brew install librsvg
This installs the libRSVG formulae, and all it’s dependencies, and makes rsvg-convert available.
Once libRSVG installed locally, you can mass-convert .svg files by running the following command in your terminal of choice.
for i in *; do rsvg-convert $i -o `echo $i | sed -e 's/svg$/png/'`; done
This loops through every .svg file in the current directory, and creates .png versions of them, for usage elsewhere.