From Optflux
If you’d rather do without the headache of downloading a specific youtube downloader to download your chosen YouTube video, you can always make use of an online tool. Though there are a number of web-based download platforms for YouTube, GetanyVideo is our current favorite. It’s neat and fast and won’t perhaps you have clicking through pages which spawn popups or another intrusive ads.
Step one: Obtain the YouTube video you need to download and copy its URL in the address bar near the top of your browser window.
Step 2: Visit the GetanyVideo webpage.
Step 3: Paste it to the bar that reads “Enter the video's link...”
Step 4: Select your preferred video format and click on the respective blue “Download” button around the right-hand side.