Virtualized Lists
Rendering 50,000 DOM rows is expensive even if each row is simple. Virtualization renders only the visible window plus a small buffer.
Virtualized lists require careful handling of item measurement, keyboard navigation, focus, dynamic heights, and accessibility. A virtualization library can solve much of the complexity.
Do not virtualize tiny lists just because the technique is available. It adds implementation complexity and can interfere with browser-native behavior if used carelessly.
Key Takeaways
- Virtualization limits DOM work for very large collections.
- Accessibility and keyboard navigation must remain correct.
- Use it when list size makes normal rendering expensive.