Intercom is an American software company that produces a messaging platform which allows businesses to communicate with prospective and existing customers within their app, on their website, through social media, or via email.
WhatsApp Business is a free to download app available on Android and iPhone using which businesses can connect with their customers.
5 sites run both Intercom and WhatsApp Business Chat. That is 1% of the sites using Intercom, the smaller of the two.
Want to know which one a particular site uses? Look it up and see its whole stack, or compare two sites side by side.