Facebook APIs provide developers with tools to utilize unique Facebook features on their platforms, shortening coding time and enabling access to features such as managing page content, messenger, and live streaming without manual coding. The best Facebook API for generating hashtags is Hashtagy - Generate Hashtags, which provides a database of relevant hashtags used on social media, analyzing hashtag content to determine overall success, and alerting users when posting banned or low-performing hashtags. Other top-rated APIs include Instagram Facebook Media Downloader, TwineSocial, FacebookGraphAPI, FacebookMessenger, FacebookLiveAPI, Facebook Graph API, FacebookWorkplaceGraph API, and FacebookWorkplaceAccountManagement API. These APIs offer various features such as downloading content from Facebook and Instagram, managing social media marketing campaigns, integrating Facebook features on external platforms, and managing Facebook group membership. Most of these APIs are free to use with no associated monthly fees or request caps, making them accessible to developers and businesses looking to leverage Facebook's features in their applications.