If you ever need a quick scratchpad to just write, not save what you write, but just write, you can quickly turn your web browser into an ultra-basic notepad with a single line of HTML.
This clever trick comes from developer Jose Jesus Perez Aguinaga who says that “sometimes I just need to type garbage. Just to clear out my mind. Since I live in the browser, I just open a new tab and type”:
data:text/html, <html contenteditable>
Of course there’s no easy way to save your work, so while this is probably the most minimal editor you could hope for, it isn’t the most practical for actual work. Still a great trick though. Check out the comments on Aguinaga’s post and on this Hacker News thread for some enhancements to the basic idea (like what I used for the screenshot above) and a Chrome extension.