youtube-transcript-plus

A Node.js library to fetch transcripts from YouTube videos. This package uses YouTube's unofficial API, so it may break if YouTube changes its internal structure.
Note: This project was originally forked from https://github.com/Kakulukian/youtube-transcript.
Installation
$ npm install youtube-transcript-plus
or
$ yarn add youtube-transcript-plus
Usage
Basic Usage
import { fetchTranscript } from 'youtube-transcript-plus';
fetchTranscript('videoId_or_URL').then(console.log).catch(console.error);
Custom User-Agent
You can pass a custom userAgent
string to mimic different browsers or devices.
fetchTranscript('videoId_or_URL', {
userAgent:
'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36',
})
.then(console.log)
.catch(console.error);
HTTP Support
You can disable HTTPS and use HTTP instead for YouTube requests by setting the disableHttps
option to true
. This might be necessary in certain environments where HTTPS connections are restricted.
fetchTranscript('videoId_or_URL', {
disableHttps: true,
})
.then(console.log)
.catch(console.error);
Security Warning: Using HTTP instead of HTTPS removes transport layer security and is not recommended for production environments. Only use this option when absolutely necessary.
Custom Fetch Functions
You can inject custom videoFetch
and transcriptFetch
functions to modify the fetch behavior, such as using a proxy or custom headers.
fetchTranscript('videoId_or_URL', {
videoFetch: async ({ url, lang, userAgent }) => {
return fetch(`https://my-proxy-server.com/?url=${encodeURIComponent(url)}`, {
headers: {
...(lang && { 'Accept-Language': lang }),
'User-Agent': userAgent,
},
});
},
transcriptFetch: async ({ url, lang, userAgent }) => {
return fetch(`https://my-proxy-server.com/?url=${encodeURIComponent(url)}`, {
headers: {
...(lang && { 'Accept-Language': lang }),
'User-Agent': userAgent,
},
});
},
})
.then(console.log)
.catch(console.error);
Language Support
You can specify the language for the transcript using the lang
option.
fetchTranscript('videoId_or_URL', {
lang: 'fr',
})
.then(console.log)
.catch(console.error);
Caching
You can provide a custom caching strategy by implementing the CacheStrategy
interface. The library also provides default implementations for in-memory and file system caching.
In-Memory Cache
import { fetchTranscript, InMemoryCache } from 'youtube-transcript-plus';
fetchTranscript('videoId_or_URL', {
lang: 'en',
userAgent: 'FOO',
cache: new InMemoryCache(1800000),
})
.then(console.log)
.catch(console.error);
File System Cache
import { fetchTranscript, FsCache } from 'youtube-transcript-plus';
fetchTranscript('videoId_or_URL', {
cache: new FsCache('./my-cache-dir', 86400000),
})
.then(console.log)
.catch(console.error);
Custom Caching
If the default implementations don’t meet your needs, you can implement your own caching strategy:
import { fetchTranscript, CacheStrategy } from 'youtube-transcript-plus';
class CustomCache implements CacheStrategy {
async get(key: string): Promise<string | null> {
}
async set(key: string, value: string, ttl?: number): Promise<void> {
}
}
fetchTranscript('videoId_or_URL', {
cache: new CustomCache(),
})
.then(console.log)
.catch(console.error);
Error Handling
The library throws specific errors for different failure scenarios. Make sure to handle them appropriately.
import {
YoutubeTranscriptVideoUnavailableError,
YoutubeTranscriptDisabledError,
YoutubeTranscriptNotAvailableError,
YoutubeTranscriptNotAvailableLanguageError,
} from 'youtube-transcript-plus';
fetchTranscript('videoId_or_URL')
.then(console.log)
.catch((error) => {
if (error instanceof YoutubeTranscriptVideoUnavailableError) {
console.error('Video is unavailable:', error.message);
} else if (error instanceof YoutubeTranscriptDisabledError) {
console.error('Transcripts are disabled for this video:', error.message);
} else if (error instanceof YoutubeTranscriptNotAvailableError) {
console.error('No transcript available:', error.message);
} else if (error instanceof YoutubeTranscriptNotAvailableLanguageError) {
console.error('Transcript not available in the specified language:', error.message);
} else {
console.error('An unexpected error occurred:', error.message);
}
});
Example Usage Files
The repository includes several example files in the example/
directory to demonstrate different use cases of the library:
basic-usage.js
: Demonstrates the simplest way to fetch a transcript using the default settings.
caching-usage.js
: Shows how to use the InMemoryCache
to cache transcripts with a 30-minute TTL.
fs-caching-usage.js
: Demonstrates how to use the FsCache
to cache transcripts on the file system with a 1-day TTL.
language-usage.js
: Shows how to fetch a transcript in a specific language (e.g., French).
proxy-usage.js
: Demonstrates how to use a proxy server to fetch transcripts, which can be useful for bypassing rate limits or accessing restricted content.
These examples can be found in the example/
directory of the repository.
API
fetchTranscript(videoId: string, config?: TranscriptConfig)
Fetches the transcript for a YouTube video.
videoId
: The YouTube video ID or URL.
config
: Optional configuration object with the following properties:
lang
: Language code (e.g., 'en'
, 'fr'
) for the transcript.
userAgent
: Custom User-Agent string.
cache
: Custom caching strategy.
cacheTTL
: Time-to-live for cache entries in milliseconds.
disableHttps
: Set to true
to use HTTP instead of HTTPS for YouTube requests.
videoFetch
: Custom fetch function for the video page request.
transcriptFetch
: Custom fetch function for the transcript request.
Returns a Promise<TranscriptResponse[]>
where each item in the array represents a transcript segment with the following properties:
text
: The text of the transcript segment.
duration
: The duration of the segment in seconds.
offset
: The start time of the segment in seconds.
lang
: The language of the transcript.
Errors
The library throws the following errors:
YoutubeTranscriptVideoUnavailableError
: The video is unavailable or has been removed.
YoutubeTranscriptDisabledError
: Transcripts are disabled for the video.
YoutubeTranscriptNotAvailableError
: No transcript is available for the video.
YoutubeTranscriptNotAvailableLanguageError
: The transcript is not available in the specified language.
YoutubeTranscriptInvalidVideoIdError
: The provided video ID or URL is invalid.
License
MIT Licensed