mkdir youtube-downloader

cd youtube-downloader

npm init -y

npm install express ytdl-core

GET http://localhost:3000/getVideoInfo?url=YOUTUBE_VIDEO_URL

http://localhost:3000/download?url={YOUTUBE_VIDEO_URL}&itag={FORMAT_ITAG}

 const express = require('express');

const ytdl = require('ytdl-core');

const cors = require('cors');

const app = express();

const PORT = 3000;

app.use(cors());

app.use(express.json());

// Endpoint to get video details and available download options

app.get('/getVideoInfo', async (req, res) => {

    const videoURL = req.query.url;

    if (!videoURL) {

        return res.status(400).json({ success: false, message: 'YouTube video URL is required' });

    }

    try {

        if (!ytdl.validateURL(videoURL)) {

            return res.status(400).json({ success: false, message: 'Invalid YouTube video URL' });

        }

        const videoID = ytdl.getURLVideoID(videoURL);

        const info = await ytdl.getInfo(videoID);

        const formats = info.formats.map(format => ({

            itag: format.itag,

            quality: format.qualityLabel || 'Unknown',

            mimeType: format.mimeType.split(';')[0],

            hasAudio: !!format.audioBitrate,

            hasVideo: !!format.qualityLabel,

            container: format.container,

            url: `/download?url=${videoURL}&itag=${format.itag}`

        }));

        res.json({

            success: true,

            videoDetails: {

                title: info.videoDetails.title,

                author: info.videoDetails.author.name,

                lengthSeconds: info.videoDetails.lengthSeconds,

                thumbnails: info.videoDetails.thumbnails,

            },

            availableFormats: formats

        });

    } catch (error) {

        res.status(500).json({ success: false, message: 'Failed to retrieve video information', error: error.message });

    }

});

// Endpoint to download the selected video format

app.get('/download', (req, res) => {

    const videoURL = req.query.url;

    const itag = req.query.itag;

    if (!videoURL || !itag) {

        return res.status(400).json({ success: false, message: 'Invalid request, YouTube video URL and itag are required' });

    }

    if (!ytdl.validateURL(videoURL)) {

        return res.status(400).json({ success: false, message: 'Invalid YouTube video URL' });

    }

    try {

        res.header('Content-Disposition', 'attachment; filename="video.mp4"');

        ytdl(videoURL, { quality: itag }).pipe(res);

    } catch (error) {

        res.status(500).json({ success: false, message: 'Failed to download the video', error: error.message });

    }

});

app.listen(PORT, () => {

    console.log(`Server is running on http://localhost:${PORT}`);

});