Educators can take inspiration from this. Providing students with starter code or exemplar solutions to copy can jump-start the learning process. In this sense, copy-paste is a form of apprenticeship: ...

Boffins affiliated with dev tools biz JetBrains and HSE University in Moscow have devised an open-source plugin for the company's Java development editor that guards against copy-and-paste coding.

All you have to do is visit Paste HTML, enter some code, publish it, and look at what you made. Paste HTML supports HTML, CSS, and JavaScript. You can even use Markdown if you want.