sdcard[.]org/downloads/formatter_4/
This is from the SD Association itself, written by Tuxera Inc., and what they recommend rather than the built-in app(s) on your PC/laptop, which allegedly can be not so great for your SD cards.
wikipedia[.]org/wiki/Tuxera
The app itself seems to be fully portable, but the setup file kinda stinks. You have a setup file that unpacks a .msi file that adds 2 files & a Start Menu shortcut, **along with a couple hundred new registry entries, plus a couple of copies of that .msi file added to Windows folders**. That likely won't bother most folks, but if you have a VM handy you might want to use it in this case.