Nuxt.js let you define all default meta for your application inside nuxt.config.js, use the same head property

• Type: Object or Function

nuxt.config.js

export default {
  head: {
    titleTemplate: '%s - Nuxt.js',
    meta: [
      { charset: 'utf-8' },
      { name: 'viewport', content: 'width=device-width, initial-scale=1' },
      // hid is used as unique identifier. Do not use `vmid` for it as it will not work
      { hid: 'description', name: 'description', content: 'Meta description' }
    ]
  }
}

To know the list of options you can give to head, take a look at vue-meta documentation.

You can also use head as a function in your components to access the component data through this (read more).

To avoid duplicated meta tags when used in child component, set up a unique identifier with the hid key for your meta elements (read more).