Why building a reliable inline rich text editor is still surprisingly hard

Rich text editing on the web looks like a solved problem — until you try to build something that works reliably in real-world apps. On paper, browsers have had contenteditable for years. In practice, once you start building production features around it, things get weird very fast. The illusion of “it just works” Simple demos usually work fine: Type text Select text Click bold Done But real users don’t edit like demo users. They: Double click words Triple click paragraphs Select backwards Select across multiple nodes Paste random formatted content Edit inside nested elements That’s where things start breaking. The hardest part isn’t UI — it’s selection Most of the complexity I’ve seen comes from selection handling: Different browsers return slightly different selection ranges. Collapsed selections behave differently. Multi-node selections are inconsistent. Toolbar state can easily desync from actual formatting. And once your toolbar shows the wrong state — users lose trust instantly. B