I Eliminated Layout Jitter From LLM Streaming — Here's How

Every AI chat app has the same bug. You've felt it. That stuttering scrollbar, the content jumping, the dropped frames when tokens stream in. I spent weeks building a library that makes it physically impossible. The Problem Nobody Talks About Open ChatGPT. Claude. Gemini. Any LLM-powered chat interface. Now watch the scrollbar while the model streams a response. See it? That micro-stutter. The scrollbar jumps. The content reflows. If you're on a slower device, you'll see actual frame drops. It's subtle on short responses, but stream 500+ tokens and it becomes infuriating. Why does this happen? Every single token that arrives triggers the same cascade: Token arrives → DOM mutation → Style recalculation → Layout reflow → Paint → Composite At 50 tokens/second, that's 50 full layout reflows per second . Each one forces the browser to: Recalculate every CSS property that could be affected Recompute the geometry of every element in the render tree Determine what pixels need repainting Compos