The instant search feature at Zero Dollar Movies uses the YouTube data API to find free movies on the YouTube website.
When the user enters a search query, the script makes a request to the gdata.youtube.com (YouTube data API) for search results. The resultset is returned in JSON format. The code uses YouTube API v2 and, while optional, it may be a good idea to include a developer key in the API requests.
Generate a YouTube Developer Key
You can go to the Google API console to create a developer key for your project. Go to cloud.google.com/console and start a new project. Give your project a unique name and then choose APIs to turn on the YouTube Data API. Next create a new key under Public API access, set the type as Browser key and the website referrer as your website address (to prevent abuse).
YouTube Data API Quota Limits
YouTube Data API v3’s quota is 50,000,000 units per day. The quota cost of making a single search request to YouTube is just 2 units and thus a normal web application is unlikely to exceed the quota anytime soon.
You can also enable billing the Google Cloud console to further increase your quota.