Editor's note: Be sure to check out our research on the overall growth of Web APIs since 2005. At the time of writing, this is the most recent data we have, but check the research page to see if we have a more updated article. We will be continually updating the overall growth chart with other charts getting updated on a less frequent basis.
One of the more interesting views given by the directory is a look at what sectors are seeing the most growth in APIs. The first, most obvious thing to look at is which categories are most represented in the directory. One thing to note is that, for each API, our data model allows for one primary category as well as multiple secondary categories. When looking at the most popular categories, across both primary and secondary, we get the graph below.
We see the the Social category leads the way with 1,485 APIs. This isn't surprising given the sheer number of social apps that have appeared over the last decade. Some of the most recognized companies including FacebookTrack this API, TwitterTrack this API and LinkedInTrack this API have multiple APIs in this category.
Financial is another category that has seen a surge in interest around APIs. The open banking trend is one that had been slow to happen but now seems to be moving at an accelerated pace. ProgrammableWeb analyst Mark Boyd has cited studies stating that “the majority of banks recognize that an open banking platform is the endgame for the industry.” That recognition combined with regulatory pressure such as PSD2 has meant that more Financial APIs than ever are now being released. With no pressure at all from domestic regulators (as has been the case in Europe), US-based financial institutions like Capital One have come bursting out of the gate with open API programs in 2016.
While most of the categories in the top ten are expected, the Tools category, with 1,388 APIs, is a bit of a surprise. A closer look into this category shows a wide range of API functionality such as a keystroke resolver and software tool comparisons. The variety of APIs within this category may mean that the Tools category is viewed by providers who list their APIs in our directory as a bit of a catch-all. This clearly points to evolutionary opportunities to improve our taxonomy (always an ongoing process).
We can limit our data to show the most popular categories only when they are listed as the primary category.
The top ten looks very similar with the additions of Payments, Government and Reference. The growth of Government APIs is likely a natural result of several factors; chief among them being the Obama administration's mandate that all government generated data be machine readable. As a side note, we, like many others, wonder about the future of that mandate now that there’s been a change in administration. The Payments category growth ties closely to the growth of FinTech and Open Banking discussed above.