When working with Vue components, one of the best features you get out of the box is scoped CSS. It keeps your styles neatly contained inside a component, so you don’t have to worry about a single misplaced class messing up layouts elsewhere in your app.
But sometimes, you actually need to break out of that scope — for example, when you’re using a third-party component or library that injects its own internal classes, and you want to tweak those styles directly.
That’s where ::v-deep comes in.
What is ::v-deep?
::v-deep is a special scoping selector introduced in Vue 3, designed to let you target child components’ DOM elements that would normally be “hidden” behind Vue’s scoped style encapsulation.
In simple terms, it tells Vue’s compiler:
“Hey, I know this style is scoped, but I need to reach inside this component and apply a CSS rule there.”
How It Works
Normally, when you add scoped to your <style> tag, Vue automatically generates unique attributes to isolate each component’s CSS. That’s great for avoiding conflicts, but it also means you can’t easily style deep child elements.
Let’s say you’re using a third-party component — maybe a date picker — and you want to change the color of one of its internal elements:
<template>
<DatePicker />
</template>
<style scoped>
::v-deep(.date-picker__day--selected) {
background-color: #42b983;
color: white;
}
</style>
Here, ::v-deep lets you safely override that internal class without removing scoped styles entirely.
Why It’s Useful
There are plenty of cases where ::v-deep comes in handy:
- When customizing styles for third-party UI components (like Vuetify, Element Plus, or custom pickers)
- When working with slots and you need to target elements rendered inside the slot
- When you want to keep your styles scoped but still make local adjustments to nested components
It’s especially valuable because it strikes a balance — you get the safety of scoped styles while still having the flexibility to fine-tune your UI.
A Few Notes of Caution
::v-deep is powerful, but it should be used sparingly. Overusing it can quickly blur the boundaries between components, making your CSS harder to maintain and reason about.
If you find yourself relying on it often, that might be a sign that your component hierarchy or styling structure could use a small refactor.
Also, if you’re working on a Vue 2 project — ::v-deep is not officially available there, but you can achieve similar results using the older /deep/ or >>> combinators. However, those are deprecated and not recommended for new projects.
Wrapping Up
::v-deep isn’t something you’ll need every day, but when you do, it’s a real lifesaver. It gives you just enough control to fine-tune third-party styles or nested components without throwing away the benefits of scoped CSS.
In short — use it wisely, and your components will stay both clean and flexible.