Originally published on danholloran.me
The virtual DOM has been Vue's engine room since day one. It's the layer that diffs what changed in your component tree and figures out the minimal DOM updates needed. For most apps, it's fast enough that you never think about it. But "fast enough" has always meant there was overhead you were silently paying — and now Vue is letting you opt out.
Vue 3.6 ships Vapor Mode as a stable, opt-in compilation strategy. Components that use it skip the virtual DOM entirely. Instead of generating VNodes that get diffed at runtime, the compiler generates direct DOM operations — the same approach that makes SolidJS and Svelte 5 so fast. The benchmarks are striking: up to 97% faster renders in component-heavy scenarios, with bundle sizes 20–50% smaller for Vapor-only components. Vue can now mount 100,000 components in roughly 100ms, which puts it squarely in the same performance tier as SolidJS.
How Opting In Works
The upgrade path is intentionally low-friction. You don't switch your whole app at once. Vapor is a per-component choice, and it coexists freely with your existing virtual DOM components in the same tree.
