Due to the ubiquitous problem of tab overload, I need a way to remind myself what a browser window is for. I tried labelling tab groups in Chrome, but that gives me almost no space to work with. I thought I was going to have to install (and trust) an extension. So I was pleased to find a hack at the top of https://www.makeuseof.com/tag/use-browser-notepad/ I customized it a bit though.
Paste this into your browser's address bar (the separate lines will merge), then bookmark the resulting "page".
You'll have a page with just a single, large textarea (which will have cursor focus). Just start typing whatever you want.
It'll all disappear when you close the tab, which for my use case is a feature, not a bug.