73. ytdown.to [youtube] [downloader] [audio] [s4.ytcontent.net]

/*
base  : https://ytdown.to/en2/
nama  : yutub audio downloader,
node  : v24.11.1
update: 9 desember 2025
note  : skrep nya cuma sup audio
todo  : nambahin param biar bisa download video

enjoy
*/

const yt = {
    _getInfo: async function (youtubeUrl) {
        const headers = {
            "content-type": "application/x-www-form-urlencoded; charset=UTF-8",
            "accept-encoding": "gzip, deflate, br, zstd"
        }
        const body = 'url=' + encodeURIComponent(youtubeUrl)
        const api = 'https://ytdown.to/proxy.php'
        const r = await fetch(api, { headers, body, method: 'post' })
        if (!r.ok) throw Error(`${r.status} ${r.statusText} di fungsi getInfo`)
        const j = await r.json()
        return j
    },

    _download: async function (getInfoObject) {
        const audio128url = getInfoObject.api.mediaItems.filter(m => m.mediaQuality === '128K')?.[0]?.mediaUrl
        if(!audio128url) throw Error ('tidak ada audio')
        const a = await this._getInfo(audio128url)
        return a
    },

    download: async function (youtubeUrl) {
        const getInfoObject = await this._getInfo(youtubeUrl)
        const result = await this._download(getInfoObject)
        return result
    }
}

// cara pakai
yt.download('https://www.youtube.com/watch?v=By7ctqcWxyM')
    .then(console.log)
    .catch(console.log)

/* output
{
  api: {
    percent: 'Completed',
    fileSize: '2.90 MB',
    fileName: 'YTDown.com_YouTube_Sum-41-Pieces_Media_By7ctqcWxyM_008_128k.m4a',
    estimatedFileSize: '2.90 MB',
    fileUrl: 'https://s4.ytcontent.net/v3/d/audio/By................6bb6b01dbf20ab0'
  }
*/