useState vs SolidJS createSignal — Re-render Model vs Fine-Grained Reactivity

createSignal and useState both trigger a full re-execution of the enclosing component function on update; the only difference is syntax.

useState triggers a full re-render of the component function and relies on virtual DOM diffing to determine what changed, while createSignal is a fine-grained reactive primitive that updates only the specific DOM nodes depending on it, without re-running the component function at all.

createSignal is slower than useState because it lacks a virtual DOM to batch updates efficiently.

useState updates the DOM directly without any intermediate diffing step, making it functionally equivalent to createSignal.