I’m dusting this blog off to write up some of my side projects from the past few years, and I notice I still have a link to to RSnake’s now-dead “XSS Cheat Sheet” page. To this day, I still try to bring that site up just to use the little Javascript calculators at the bottom of the page.
There is still mirror of the original site on archive.org, but I’ve ripped out just the Javascript calculators and put them here as a single file:
https://www.awgh.org/pxsscs.html
Use it from the site, or download it and use it locally. You can even add the list of XSS string suggestions back in if you want to, although the maintained version now lives at OWASP (although the OWASP version is missing the calculators).