Nearly 90% of developers use APIs, found a recent SlashData survey.

The global developer community is growing rapidly. In fact, based on our on-going developer population sizing research, we estimate that it has grown by 27% over the past two years, counting 21.3 million developers in Q3 2020. We expect this number will increase further to 23.6 million developers by Q3 2021. One of the many questions that come with this observation is: How has the usage of the various development tools changed as a result of the developer population boom?

When it comes to the usage of APIs, they have increased exponentially in many software sectors. For example, the use of Machine Learning APIs in Augmented and Virtual Reality (AR/VR) increased by 4% percentage points from 14% to 18% from Q1 to Q3 2020.

There Are 19.1 Million API Developers in the World

In our 19th Developer Economics survey, which closed in Q3 2020 and reached more than 17,000 developers globally, we asked developers whether or not they use APIs, and of which category. Based on the responses to our survey, only 11% of developers don’t use APIs, which means (as there are 21.3M developers in total) that 19.1M developers use APIs in their projects. The majority (69%) use third-party APIs, while one in five (20%) use only private or internal APIs.

The fact that nearly 90% of developers use APIs goes quite a long way to prove that the emergence of APIs has been a critical factor behind the developer ecosystem boom in the past few years. APIs abstract away the complexity of low-level software layers, enabling developers to focus on the core functionality of their applications. As such, APIs both lower the barrier to entry for inexperienced developers and increase efficiency for the more experienced ones in all the cases where they would typically intervene and customize things at the low-level.

Nearly 90% of developers use APIs.

But these overall usage trends are only the tip of the iceberg. To truly understand the impact that APIs are having, one needs to dive deeper into the ‘what,’ the ‘who,’ and the ‘how.’ Which types of third-party APIs are developers mostly using? Who is not using APIs? Which profile of developers only use private APIs? How are developers using APIs, and in which types of projects? What are they looking for in APIs, and what challenges are they facing?

Our research does answer all of these questions and goes deep into profiling API users. For the purpose of this article, however, we address the first two questions: Which are the most popular types of APIs, and who is using versus not using APIs.

Location and Payments Are the Most Popular API Categories

In our survey, we track 17 different categories of third-party APIs. Out of these, three stand out as the most popular: Location & mapping, payments, and email APIs. More than one in three developers who use third-party APIs use each of these categories.

In addition, we found that, on average, developers use 2.9 APIs, including private and internal ones. This implies that APIs have penetrated several aspects of development, facilitating the addition of several different features to apps through the usage of multiple APIs.

Location, payments, and email APIs are used by one in three API developers.

Although they didn’t make it to the top 10 by a very narrow margin, finance and banking APIs are also quite popular, used by 17% of API developers. Considering this statistic alongside the broad adoption of payment APIs, we gain some perspective into the present and future of mobile and financial services. If nothing else, it becomes evident that security concerns over the use of open banking APIs are not shared by a sizable proportion of the developer community that invests in them as part of their app offering.

Looking at the types of APIs that make it to the top, it’s clear that the dominant kind is APIs related to the most established means of communications, especially within a business setting, and also those that don’t rely as heavily on a fast and reliable internet connection. Email and messaging APIs, for example, are way ahead of video and voice (which didn’t even make it to the top 10).

Professionals Make Heavier Use of APIs

As mentioned earlier, it is important to go beyond the big picture to understand which developer profiles use APIs more than others. Doing so allows you to better target developer segments with the right messaging, leading to a higher overall return on your developer marketing efforts.

Going just one level deeper to split developers by their professional status, we already see differences in behavior. Professional developers (defined as those who are professionally involved in at least one development area) are far more likely to be using APIs than those who are into coding only as hobbyists or students: 93% of professional developers use APIs, as compared to 80% of students or hobbyists.

Nearly three in four professionals use third-party APIs.

While the two groups don’t differ in the number of APIs they use on average (2.9), professionals use private or internal APIs more and use public APIs less than hobbyists and students. When we exclude those in both groups who don’t use any APIs, we find that 77% of professionals, as compared to 80% of hobbyists and students, use third-party APIs. This makes sense, as professionals are more likely to invest in private APIs or work within organizations that have built their own internal APIs.

How Do API and Non-API Developer Communities Differ?

The above analysis is obviously just the starting point in exploring the expanding API space. Much more can be said about who uses APIs, where they are located, and technology trends. ML APIs are rapidly gaining traction, for example. For other key API developer statistics, watch the Nordic APIs LiveCast Developer Empathy. In it, we explore more statistics on how API and non-API developers differ and cover tactics for developer segmentation.