Download all of the thumbnails of all YouTube videos of the selected channel

download-thumbnails.js

const axios = require('axios'); // `npm i axios` or `yarn add axios`
const fs = require('fs');

const apiKey = '(API KEY HERE)';
const channelId = '(CHANNEL ID HERE)';

async function getParams(extra) {
    return (await axios.get(`https://youtube.googleapis.com/youtube/v3/search?part=snippet&channelId=${channelId}&maxResults=50&order=date&safeSearch=none&type=video&key=${apiKey}${extra}`)).data;
}

(async () => {
    let extra = '';
    do {
        const result = await getParams(extra);

        Promise.all(result.items.map(async ({ id: { videoId }, snippet: { publishedAt } }) => {
            try {
                const date = publishedAt.split('T')[0];
                (await axios({ method: 'get', responseType: 'stream', url: `https://img.youtube.com/vi/${videoId}/maxresdefault.jpg` })).data.pipe(fs.createWriteStream(`thumbnails/${date}.png`));
            } catch (error) {}
        }));

        extra = result.nextPageToken ? '&pageToken=' + result.nextPageToken : '';
    } while (extra);
})();