NumberFlow

Reach for NumberFlow any time a displayed number changes and the change should be legible — pricing toggles, live counters, stat tiles, cart totals, usage meters — instead of hand-rolling a count-up with a spring library. It composes with anything because the core is a custom element with zero dependencies: install @number-flow/react, @number-flow/vue or @number-flow/svelte to match the host app, and use the plain `number-flow` package outside a framework. Two gotchas: pass formatting through the `format` prop as Intl.NumberFormatOptions rather than pre-formatting the string, or the digit diffing breaks; and wrap instances in NumberFlowGroup when one animating number shifts another's position, otherwise their transitions desync.

Why it is here. The reference implementation for animated numbers on the web — four framework bindings, no dependencies, motion-preference aware, and 7.6k stars behind it. There is no reason to write this yourself.