Just like any core piece of your application and architecture, APIs require a specific set of tools to ensure they are running smoothly. The main part of this tool set is API monitoring tools, which can help ensure that APIs are performant and detect potential issues, including runtime security issues.
In this blog, we will look at 15 of the most popular API monitoring tools. However, before we dive into some of the specific tools you might deploy for API monitoring, we should answer the obvious question - what even IS API monitoring in the first place?
What is API Monitoring?
API monitoring is the process of gathering data, visualizing it, and building alerts and functionality based on the telemetry data reported from an API (or Application Programming Interface). This process ensures that API requests are handled as expected, allowing for the generation of infrastructure metrics, real user monitoring, integration tests, and much more.
There's a few obvious benefits of API monitoring - notably an increase in the visibility of the entire platform. But beyond the immediate benefits, there are some not-so obvious tack-on benefits that really make this process worthwhile.
First and foremost, API monitoring plays an important role in helping teams surface API-related issues, such as errors, issues with latency, and security vulnerabilities, before they become a more significant problem and negatively impact services, partners, and customers.
Secondly, this process can point to symptomatic issues that may not directly affect your API but certainly impact your customers. An effective testing regime can surface issues with external APIs, integration system performance, security considerations with partner APIs, and even secondary platforms such as mobile app testing.
Key API Metrics to Monitor
It's important to remember that the ultimate goal of API monitoring is to generate long-term or instant actionable insights - as such, the key metrics you track are going to play a huge role in the efficacy of the system, not to mention the API errors that you can actually track.
For the purposes of this guide, we've broken these metrics into some general categories. That being said, specific measurements beyond these fundamental metrics may be appropriate depending on your specific use case.
Uptime and Availability
Uptime is a relatively fundamental metric in API monitoring, representing the average amount of time that a service has been live. This, combined with availability, or the average amount of time that a live service has been usable, represents strong metrics that point towards the health of a service.
Let's look at an example. A 99.999%, or "five nines" uptime, suggests that a service has been live for 99.999% of the time. A service that has been live 99% of the time, or "two nine's", has only been live 99% of the time.
That might seem like a small difference, but if you do the math, it certainly adds up - a "five nine's" service means that across the 8,760 hours in a year, a service was available for 8759.9 hours. For a "two nine's" service, it was only available for 8672.4 hours, meaning it was down for 87.6 hours, or almost 3 and a half days.
Availability and uptime monitoring can be done across a whole service or specifically focused on a given API endpoint for granularity. High API uptime and availability of the whole service point towards a healthy codebase and operational environment.
Response Time and Latency
Response time is the time it takes for an API to process a request and return the response to the requesting client. This value is a relatively good estimate of the state of the network between the server and the client, but it can be affected by many internal factors. Latency is a good metric to pair with this, as it reflects the delay between the request and the response and is very much focused on the internal state of the service.
In context, these two give a great view of the health of the service as well as the general health of the environment in which it operates, the network timing data, and even potential client faults or delay with multiple requests. Specific browser tests can then be deployed to find if these issues are universal or specific to a given build or interface, increasing awareness and giving options for improvement.
Minimizing latency and response time ultimately results in better performance for the end user, and when you use the proper methodologies - such as caching, geolocating resources closer to clients in cloud-based systems, optimizing API transactions, etc. - this ultimately results in significantly optimizing application performance.
Resource Usage
Another huge data source has to do with your resource usage. This usage includes the use of things like network bandwidth as well as local resources such as memory and CPU utilization. These metrics will help you understand how efficient your system is, and in the context of the size of the system and the number of third-party APIs or integrations, can also help you understand whether the issue arises from your API calls, your API functionality, or something further down the pipeline like the network standards or transit environment.
A lot of this data can be sourced at the same time that you're doing your infrastructure monitoring, as they're often part and parcel with one another. High CPU usage can have a huge impact on latency, for example, as it suggests that your system is either not adequately resources or that it is inefficiently designed.
These performance monitors can give you an idea of proper scalability as well, pointing both towards general inefficiencies as well as potential for improvement to server resourcing.
15 API Monitoring Tools
With all of this understood, let's look at 15 common tools for monitoring APIs.
1 - Postman API Monitoring
Provider: Postman
Summary: As part of their popular API toolset, Postman offers a relatively comprehensive system for testing and monitoring at scale. It's a relatively strong solution, offering real-time alerting and a decently easy setup process, but it's most ideal for those already utilizing Postman for API development.
Pros
Easy to integrate with Postman workflows
Strong real-time alerting solution
Decently simple setup means you can get started quickly
Cons
Offers little in the way of advanced monitoring
Better suited for people already utilizing Postman - it's less strong a solution for those not in that ecosystem
2 - New Relic One
Provider: New Relic
Summary: New Relic One is a relatively comprehensive platform for monitoring and observability, offering real-time performance monitoring for real-time insights. It’s highly customizable and integrates well with multiple services, though it may require a learning curve for optimal use.
Pros
New Relic One is a comprehensive monitoring suite
Offers high-value, real-time data
Offers a ton of options for integration with different services
Cons
Can be expensive, especially depending on the complexity of your backend
Can be very complex to set up initially
3 - Datadog API Monitoring
Provider: Datadog
Summary: Datadog’s API monitoring provides a full view of distributed systems, allowing you to set custom alerts and track performance across a varied environment. Its dashboard is flexible and detailed, though usage-based pricing may make it costly for high-demand environments.
Pros
Excellent for distributed systems
Highly customizable alerts make it easy to track specific metrics
A flexible dashboard allows anyone to generate insights with relative ease
Cons
Pricing is based on usage, which can be costly
While it's easy to get started, it has a steep learning curve to really get the most out of the service
4 - Uptrends
Provider: Uptrends
Summary: Uptrends offers uptime monitoring and performance tracking with a well-featured tool set. It includes features like browser emulation, allowing you to test a wide variety of environments and client use cases. It’s a good choice for some specific criteria, though customization options for API requests are somewhat limited.
Pros
User-friendly interface that is easy to get started with
Reliable uptime and performance checks
Browser simulation unlocks a ton of variable testing and monitoring options
Cons
Limited API request customizations
Can be costly if you end up using the complete feature set
5 - APImetrics
Provider: APImetrics
Summary: APImetrics is a specialized API monitoring tool offering SLA compliance tracking and multi-region testing. It provides deep analytics, and is especially useful for monitoring SLAs.
Pros
Comprehensive analytics system with multi-region testing
Very effective SLA compliance tracking
Cons
UI is somewhat unintuitive
APImetrics doesn't offer as complete a set of integration options
6 - Runscope
Provider: CA Technologies
Summary: Runscope excels at debugging and tracking HTTP requests, making it ideal for tracking API performance across the network. However, advanced monitoring features are limited, and it can be costly for larger teams.
Pros
Great for debugging and efficiency hunting
Allows HTTP request/response tracking
Designed with team collaboration in mind
Cons
Limited advanced features beyond the collaborative tooling
This collaborative tooling comes at a high cost, which can be prohibitive for large teams
7 - Prometheus
Provider: Cloud Native Computing Foundation
Summary: Prometheus is an open-source, customizable tool designed specifically for time-series data. It’s relatively popular among developers who need high flexibility, though it requires significant setup expertise and isn’t as user-friendly as other options on the market.
Pros
An open-source tool, which makes it highly customizable and cheap to utilize
Great specifically for time-series-centric data
Cons
Relatively difficult to get set up, as there's no product bundling common with enterprise software offerings
Not as user-friendly as the plug-n-play solutions on this list
8 - API Fortress
Provider: API Fortress
Summary: This tool offers a no-code setup and strong integration options, making it accessible for teams without extensive coding knowledge. API Fortress is very particular in terms of its design and workflow, however, and the UI can be challenging for new users.
Pros
API Fortress offers a ton of options for integration
The load testing tooling is pretty feature-rich
No-code automation brings the benefits of automation to teams that might not otherwise have that skillset
Cons
The UI can, at times, be overwhelming, making it hard to track essential metrics without prior experience
9 - Kong Enterprise
Provider: Kong Inc.
Summary: Kong provides API gateway and management services with additional built-in tooling for API monitoring. It’s well-suited for enterprise environments, but it might be too complex for smaller teams, less complex services, and beginners just starting their development journey.
Pros
Since Kong is a feature set rather than a single tool, it has a ton of key features that make gathering performance data, managing multiple locations, and monitoring API calls relatively easy
It's highly customizable for a variety of environments and use cases
Cons
Although you may not be ready to buy wholesale into the Kong ecosystem, the management services are bundled together, introducing excess cost and management
You can do a lot with Kong, but to really get optimal performance out of it, you need significant prior technical knowledge
10 - AWS CloudWatch
Provider: Amazon Web Services
Summary: AWS CloudWatch is specifically designed for AWS users to generate detailed performance metrics across their deployment, offering customizable alerts and deep context. It's not beginner-friendly, however, and the focus on AWS - as well as the associated cost - can be a deal breaker.
Pros
This is by far the most seamless solution for AWS ecosystem APIs, providing granular data and customizable alerts across external and internal APIs
Its log management solution is second to few, providing ample information alongside dedicated visualization tools
Cons
CloudWatch is powerful, but this power comes with cost - both in terms of money and in terms of the expert knowledge required for its use
This is a solution that is plugged directly into the AWS world - Google Cloud APIs and other third-party solutions will find this less than useful
11 - Ghost Inspector
Provider: Ghost Inspector
Summary: Ghost Inspector is specifically designed for functional API testing and monitoring, focusing on browser-based visual regression tests. It’s easy to use but lacks in-depth API monitoring metrics outside of this niche use case.
Pros
Great for functional API tests, browser-based tests, and regression tests, all of which are typically underserved by "one-stop shop" solutions
Cons
Limited advanced API monitoring metrics limit its API usage to basic awareness of API endpoints and specific types of tests
It does really well at a few things, but it's not really a comprehensive API monitoring solution
12 - Catchpoint
Provider: Catchpoint
Summary: Catchpoint is a tool that provides reliable global monitoring as well as detailed troubleshooting data. It’s a powerful tool, but it can rapidly become to expensive for small teams. It is also relatively complex to get up and running, which can be a blocker for all but the most experienced teams.
Pros
Catchpoint provides reliable data validation in addition to its monitoring suite
Reliable, detailed data for troubleshooting
Cons
Catchpoint is powerful, but it's not a very intuitive tool, which can result in a significant learning curve
It can also be quite expensive for small teams, especially due to how complex it is to initially set up
13 - Honeycomb
Provider: Honeycomb.io
Summary: Honeycomb excels at distributed tracing and is highly scalable, making it popular among larger teams. However, its pricing can be a barrier, and the complexity on offer isn't really idea for basic monitoring use cases.
Pros
Great for complex tests requiring distributed tracing or differential global endpoints
Cons
Honeycomb is another tool that is very good but very expensive - this cost might be more than a team is willing to spend (or more than a team is able to spend) for something simple, such as the need to monitor API performance or memory usage
14 - Checkly
Provider: Checkly
Summary: Checkly is an easy-to-set-up browser-based API and web monitoring solution. While intuitive, it often lacks deep analytics pathways and has limited integrations compared to more advanced tools.
Pros
Checkly is incredibly easy to get started with and remains easy to use in a variety of environments
It provides both API and general web traffic monitoring
Cons
Checkly lacks deeper analytics systems, making it hard to suggest for API failures rooted in more complex end states, systems that need more comprehensive synthetic monitoring, and so forth
Add on to this the reality that Checkly has limited integrations, and you're going to run up against limitations rather quickly
15 - UptimeRobot
Provider: UptimeRobot
Summary: UptimeRobot is a case of a product that is really simple, providing just what it says on the tin - and very little else. While it supports some good basic monitoring, it lacks detailed analytics and other advanced features.
Pros
It's highly affordable, easy to set up, and supports a wide variety of protocols
Cons
All of its pros said, it has limited API testing metrics and lacks deep, detailed analytics
Choosing the Right API Monitoring Tool
Considerations for Selecting an API Monitoring Tool
How you go about choosing the right tool to monitor APIs is going to depend largely on your given environment. Assuming you have the correct data, well-structured APIs, and systems following best practices, as well as a system that does not have a specific use case or test that it needs (which narrows your choices), you're going to want to look for the following:
Intuitive interface: a user-friendly interface that simplifies navigation and operations will be incredibly important, especially for a tool that is used by multiple teams for collaborative API monitoring. Ease of use will make your tool more likely to see use, which will make it that much more effective.
Reusability: the capability to recycle tests will make for efficient and consistent monitoring. Make sure you are able to control your code granularly instead of relying on pre-built packaged testing for improved results.
Run options: the flexibility to execute tests on-demand, to schedule testing intervals, or to launch tests in response to specific events will be very important. Make sure your chosen solution offers as many options as possible for controlling your testing regime.
Sequencing: ensure your solution allows you to control the sequencing of tests. It's not good enough to just run one mega test - you need to be able to control each test as well as the order that they are executed in order to get a full view of your data flow.
Alerts: ensure you have adequate control over notifications and alerts, setting up systems that are triggered by predefined thresholds which can indicate API performance issues or deviations. Additionally, ensure those alerts are actually useful - alerts should come with an error code, not random abstract warnings of failure!
Monitoring is Not Enough For Security!
As you read the above list of the best API monitoring tools, you might come to a simple but unavoidable conclusion - API monitoring is great but entirely reactive. Even the most comprehensive API monitoring strategy is only half the story. Monitoring is, by definition, the process of observing a failure state, and in many situations, you cannot let the failure state happen even once.
Securing your APIs before they have a huge security issue should be your number one priority, and then validating the effectiveness of that strategy should be the realm of your API monitoring regime. In that vein, how can one adequately resolve potential issues at scale?
StackHawk is an incredibly powerful testing solution that resolves this issue before you hit production. In other words, StackHawk's DAST solution shifts security left, integrating and automating within the CI/CD pipeline itself. By integrating with the DevOps pipeline, this DAST system can surface vulnerabilities before they put your production services—and your users' data—at risk.
In essence, DAST—or Dynamic Application Security Testing—is a simple and effective way to build more secure software faster and apply security principles more efficiently. StackHawk focuses on runtime and pre-production security testing, allowing you to integrate security into the development process rather than "tacking it on" as an afterthought.
Beyond the apparent technical security benefits StackHawk's DAST solution offers, StackHawk goes even further by introducing API discovery and the latest feature, API Oversight, rounding out the three core pillars of API Security. With the three core pillars, StackHawk users can ensure that every API is documented and tested and that their entire attack surface is covered—the perfect complement to a holistic API monitoring stack.
Conclusion
Monitoring is simply not enough - in order to ensure your API is performant, reliable, and secure, you need to adopt a monitoring solution that validates your security approach. With these two processes working in tandem, you can ensure a highly secure and effective production pipeline and monitoring strategy that will result in happy customers, secure databases, and solid code.
Getting started with StackHawk is incredibly easy! If you'd like to shift your security left and start building more robust and dependable code bases, you can start a free trial today!
