API usability is the degree to which developers and end users can easily understand, integrate, and work with an API. Developers who are not API specialists sometimes underestimate how much this matters. They may treat API design as a secondary task, rushing to release it as soon as it barely does what it is supposed to do instead of elaborating it thoroughly.
A rushed API is rarely taken seriously by the people who need to use it. Invest a bit more effort, however, and an API can become a powerful tool for a company — one that improves partner experience and opens opportunities for new partner connections or even entering a new market segment.
Read on to discover what to pay attention to when building a truly effective API that benefits both consumers and providers, and how ongoing API usability testing helps keep it that way.
#1 Design
Good API design starts with putting the end user's values and needs first. A truly valuable API is not only usable but, more importantly, useful. Both qualities come back to one question: "What is this particular API meant to do, and how does it do it?"
On one hand, an API should offer functionality that fits the needs of a wide range of users. On the other hand, it has to be thoroughly elaborated to ensure good API performance, avoid excessive complexity, and remain reusable, easy to understand, and easy to implement.
#2 External Testing and Prototyping
Testing a product with potential clients before release is common practice for virtually all kinds of products, and APIs are no exception. This is essentially API usability testing in practice — validating how real users interact with your API before it goes live. Special services like Peek can be a great help here, offering a quick way to learn what people think about a site or app.
Another good option is releasing the API as a beta version. This encourages users to leave feedback and be more forgiving of early bugs. Teams that lack the resources for in-house testing sometimes turn to dedicated API usability testing services to get structured, expert feedback instead.
#3 Status/Changelog and Documentation
Sometimes things go wrong. API consumers appreciate clear instructions on how to fix an error rather than being left confused by an undefined error page. It's also good practice to inform API users that something has gone wrong via email or social channels, in addition to a status page. Services like the one provided by GetResponse can help automate this kind of communication.
Designing detailed documentation is not just a worthwhile investment — it's essentially a must. A well-documented API keeps both its consumers and your customer support team happy: it's easy to understand and work with, which means fewer help requests from confused users.
#4 Velocity/Flexibility
An API can hardly be considered usable if it takes forever to return a response, no matter how well every other aspect is handled. To boost your API's performance and keep it easy to use and implement, it helps to follow advanced approaches to API building. Consider why REST is generally preferable to SOAP for maintaining API usability at scale. REST has the following advantages:
- easier to implement and maintain
- lighter and easier to use for both developers and end users
- faster to use and retrieve data
- easier to extend
- cheaper to use
Following these best practices can improve your API's performance and generate more value for users, even as usage grows.
#5 Upkeep and Enhancement
An API requires not only careful initial design but also ongoing maintenance. To keep your API functioning properly and users satisfied, attend to the following points:
- Create libraries and guides for new users — this can reduce the number of errors they run into.
- Organize a developer community through Google groups, mailing lists, or Slack channels.
- Handle versioning without disrupting users still on the previous version, until a final, scheduled deprecation.
Teams looking to reduce the ongoing engineering burden of maintaining integrations sometimes explore options like letting store owners run their store with AI tools that require no developer involvement, which shifts some of the day-to-day upkeep away from custom code.
#6 Efficiency
API providers usually focus on what an API does rather than how it does it. As a result, efficiency can end up as an afterthought, which leads to poor user experience and a negative impression. Paying attention to things like accessibility, convenience, output formats, and the speed of calls helps prevent this outcome — and is a core part of API usability testing as your API scales to more users and use cases.
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