Can I Use is a website that has documentation about browser and devices support for various features that frontend developers would use. The website provides up to date support tables on all things html, css and javascript.
The property clip-path has a global usage of 96.39%. Clip-path is used to shape an element to a basic shape or an SVG source. So far it has total support on only a few browser (Firefox, Firefox for Android, and KaiOS Browser), but it has partial support on pretty much everything else in HTML. As for CSS, it is supported in every major browser for computer and mobile.
The property box-reflect is a CSS property that is used as a -web-kit. It is pretty widely used on all major browsers as well as all major mobile browsers with the exception of Firefox. While it is a "supported" property, it is not recommended to use it. The property is used to make a reflection of an image. The reflection can be placed with a rule of above, below, right, or left.
The Can I Use website is a great tool for frontend developers to utilize when using properties they aren't familiar with. There is a ton of documentation that is up to date with browser capabilities. There is also information if there are any issues with any other properties in the CSS library. It gives a look at all new properties and where they stand in the process of being supported by browsers.