reading-time

This plugin generates word count and estimated reading time for each page.

Usage

npm i -D @vuepress/plugin-reading-time@next

.vuepress/config.ts
import { readingTimePlugin } from '@vuepress/plugin-reading-time'

export default {
  plugins: [
    readingTimePlugin({
      // options
    }),
  ],
}

The plugin injects reading time information into the readingTime field of page data:

readingTime.minutes: estimated reading time in minutes (number)
readingTime.words: word count (number)

Getting Data on Node Side

For any page, you can get estimated reading time and word count from page.data.readingTime:

page.data.readingTime // { minutes: 3.2, words: 934 }

You can access it for further processing in the extendsPage lifecycle and other lifecycles:

export default {
  // ...
  extendsPage: (page) => {
    page.data.readingTime // { minutes: 3.2, words: 934 }
  },

  onInitialized: (app) => {
    app.pages.forEach((page) => {
      page.data.readingTime // { minutes: 3.2, words: 934 }
    })
  },
}

Getting Data on Client Side

You can import useReadingTimeData and useReadingTimeLocale from @vuepress/plugin-reading-time/client to get the reading time data and locale data of the current page:

<script setup lang="ts">
import {
  useReadingTimeData,
  useReadingTimeLocale,
} from '@vuepress/plugin-reading-time/client'

const readingTimeData = useReadingTimeData() // { minutes: 1.1, words: 100 }
const readingTimeLocale = useReadingTimeLocale() // { time: "1 minute", words: "100 words" }
</script>

Options

wordPerMinute

Type: number
Default: 300
Details: Reading speed in words per minute.

locales

Type: ReadingTimePluginLocaleConfig

interface ReadingTimePluginLocaleData {
  /**
   * Word template, `$word` will be automatically replaced by actual words
   */
  word: string

  /**
   * Text for less than one minute
   */
  less1Minute: string

  /**
   * Time template, `$time` will be automatically replaced by actual time
   */
  time: string
}

interface ReadingTimePluginLocaleConfig {
  [localePath: string]: Partial<ReadingTimePluginLocaleData>
}

Details: Locale config for reading time text and word count text.

Built-in Supported Languages

Simplified Chinese (zh-CN)
Traditional Chinese (zh-TW)
English (United States) (en-US)
German (de-DE)
Russian (ru-RU)
Ukrainian (uk-UA)
Vietnamese (vi-VN)
Portuguese (pt)
Polish (pl-PL)
French (fr-FR)
Spanish (es-ES)
Slovak (sk-SK)
Japanese (ja-JP)
Turkish (tr-TR)
Korean (ko-KR)
Finnish (fi-FI)
Indonesian (id-ID)
Dutch (nl-NL)

Client API

You can import and use these APIs from @vuepress/plugin-reading-time/client:

These APIs won't throw errors even if you disable the plugin.

useReadingTimeData

interface ReadingTime {
  /** Expected reading time in minutes */
  minutes: number
  /** Words count of content */
  words: number
}

const useReadingTimeData: () => ComputedRef<ReadingTime | null>

Returns null when the plugin is disabled.

useReadingTimeLocale

interface ReadingTimeLocale {
  /** Expected reading time text in locale */
  time: string
  /** Word count text in locale */
  words: string
}

const useReadingTimeLocale: () => ComputedRef<ReadingTimeLocale>

Advanced Usage

This plugin targets plugin and theme developers, so we provide a "Use API":

your plugin or theme entry
import { useReadingTimePlugin } from '@vuepress/plugin-reading-time'

export default (options) => (app) => {
  useReadingTimePlugin(app, {
    // your options
  })

  return {
    name: 'vuepress-plugin-xxx', // or vuepress-theme-xxx
  }
}

Why you should use the "Use API"

When you register a plugin multiple times, VuePress gives you a warning that only the first one takes effect. The useReadingTimePlugin automatically detects if the plugin is registered and avoids registering multiple times.
If you access reading time data in the extendsPage lifecycle, then @vuepress/plugin-reading-time must be called before your theme or plugin, otherwise you will get undefined for page.data.readingTime. The useReadingTimePlugin ensures that @vuepress/plugin-reading-time is called before your theme or plugin.

We also provide a removeReadingTimePlugin API to remove the plugin. You can use this to ensure your call takes effect or clear the plugin:

your plugin or theme entry
import { useReadingTimePlugin } from '@vuepress/plugin-reading-time'

export default (options) => (app) => {
  // this removes any existing reading time plugin at this time
  removeReadingTimePlugin(app)

  // so this will take effect even if there is a reading time plugin registered before
  useReadingTimePlugin(app, {
    // your options
  })

  return {
    name: 'vuepress-plugin-xxx', // or vuepress-theme-xxx
  }
}