Active links

It's common for applications to have a navigation component that renders a list of RouterLink components. Within that list, we might want to style links to the currently active route differently from the others.

The RouterLink component adds two CSS classes to active links, router-link-active and router-link-exact-active. To understand the difference between them, we first need to consider how Vue Router decides that a link is active.

When are links active?

A RouterLink is considered to be active if:

1. It matches the same route record (i.e. configured route) as the current location.
2. It has the same values for the params as the current location.

If you're using nested routes, any links to ancestor routes will also be considered active if the relevant params match.

Other route properties, such as the query, are not taken into account.

The path doesn't necessarily need to be a perfect match. For example, using an alias would still be considered a match, so long as it resolves to the same route record and params.

If a route has a redirect, it won't be followed when checking whether a link is active.

Exact active links

An exact match does not include ancestor routes.

Let's imagine we have the following routes:

const routes = [
  {
    path: '/user/:username',
    component: User,
    children: [
      {
        path: 'role/:roleId',
        component: Role,
      }
    ]
  }
]

Then consider these two links:

<RouterLink to="/user/erina">
  User
</RouterLink>
<RouterLink to="/user/erina/role/admin">
  Role
</RouterLink>

If the current location path is /user/erina/role/admin then these would both be considered active, so the class router-link-active would be applied to both links. But only the second link would be considered exact, so only that second link would have the class router-link-exact-active.

Configuring the classes

The RouterLink component has two props, activeClass and exactActiveClass, that can be used to change the names of the classes that are applied:

<RouterLink
  activeClass="border-indigo-500"
  exactActiveClass="border-indigo-700"
  ...
>

The default class names can also be changed globally by passing the linkActiveClass and linkExactActiveClass options to createRouter():

const router = createRouter({
  linkActiveClass: 'border-indigo-500',
  linkExactActiveClass: 'border-indigo-700',
  // ...
})

See Extending RouterLink for more advanced customization techniques using the v-slot API.