Progressive Rendering Without Jank
Explore how to create smooth, jank-free UI updates in generative AI interfaces by managing rendering cadence and granularity. Understand techniques like buffering text updates, batching deltas, and maintaining scroll position to achieve stable and readable progressive rendering. This lesson helps you implement effective streaming visuals that balance responsiveness with layout stability.
The state machine defines when the assistant message is allowed to change. The next problem is making those changes look smooth instead of janky. A streaming panel can fail without crashing. One version updates the DOM on every token, so lines wrap differently several times per second, the container height changes, and the scroll position keeps getting corrected until the user loses their place.
A steadier version streams too, but it changes what gets rendered and when. It batches tiny deltas, flushes them at predictable points, and uses a small visual signal to show progress without constantly reshaping the layout. The work here is choosing render granularity and cadence inside the generating state, not changing how the stream is fetched.
Three primitives and what they signal
Once the janky behavior is visible, the next step is separating two timelines. The assistant can produce output continuously while the UI chooses a calmer moment to display it, which is why different progressive rendering primitives exist.
A typing indicator ...