Here are some of the code sharing websites that I found doing my research. My focus is on HTML, CSS and JS.
- Codepen
- JS Bin
- CSSDeck
- GitHub Gist
- JSFiddle. This is the one I am using. I have an account with them to test and keep my HTML, CSS and JavaScript snippets. It is very easy to generate embed code. This is how it looks:
Home page for a website