What Is API Security Testing?
Application Programming Interfaces (APIs) enable communication between applications and services. API misconfigurations and vulnerabilities can expose data. Threat actors exploit APIs as access points into systems and networks.
API security testing tools can help reduce risks and prevent breaches, designed to assess APIs and determine if the build fulfills expectations in terms of functionality, performance, security and dependability.
There is a wide range of API security testing tools available. CI/CD pipelines usually employ API automation testing tools, which provide the efficiency needed to maintain fast-paced development without compromising security.
Learn more in our detailed guide to API security testing
In this article:
Top API Security Testing Tools
Here are some notable tools for testing API security.
Bright

Bright uses a dev first approach to test APIs and web applications, so that security testing can be put into the hands of developers, to ‘shift left’. It tests a wide range of API architectures including REST API & GraphQL testing.
Bright complements DevOps and CI/CD processes, empowering developers to detect and fix vulnerabilities early and often, on every build. Bright automatically validates every security finding, removing all false positives and the need for lengthy and costly manual validation that slows down your rapid release cycles. It reduces the reliance on manual testing by leveraging multiple discovery methods:
- HAR files
- OpenAPI (Swagger) files
- Postman Collections
It allows you to detect the OWASP API Top 10 and more, seamlessly integrated across pipelines via:
- Bright Rest API
- Convenient CLI for developers
- Common DevOps tools like CircleCI, Jenkins, JIRA, GitHub, Azure DevOps, and more
Bright supports multiple authentication mechanisms to ensure coverage is maximized and uses an innovative approach to testing, to include certain Business Logic Vulnerability testing, the first of its kind.
Other notable features include:
- Free account available
- Smart Scan – automatic ‘smart’ decisions to minimize scan time, without compromising on coverage, to maintain rapid release cycles. Includes out of the box scan optimisations and templates
- Scans can be configured with yaml files
- Developer friendly remediation guidelines
- cURL commands to reproduce the attack and debug
- Execute and replay specific vulnerability attacks, removing the need to run a full re-test
Katalon Studio

Katalon Studio is an end-to-end testing automation solution for web applications, APIs, as well as desktop and mobile applications. The solution supports SOAP and REST requests, as well as a wide range of parameterization features and commands. Katalon Studio offers both UI and API/Web services for various platforms, including Windows, Linux and Mac OS.
Here are several notable features:
- API, WebUI, mobile testing, Desktop App and combined capabilities.
- Supports data-driven approaches, automated and exploratory testing, CI/CD integration and AssertJ.
- It is suitable for stakeholders of various skill sets, offering Manual and Groovy Scripting modes.
- You can integrate it with Katalon TestOps, which is a test orchestration platform.
Postman

Postman was initially a browser plugin designed for Chrome. It now offers native versions for Mac and Windows. Postman lets you test APIs without coding or even use the same language used by the developers.
Here are several notable features:
- Simple REST client
- A rich and user-friendly interface
- Suitable for automated and exploratory testing
- Can run on Windows, Mac, Linux and Chrome Apps
- Offers several integrations, including support for Swagger and RAML formats
- Provides run, test, document and monitoring features
- Allows users to package all requests and expected responses and send the package to their colleagues.
Version 7.3 and later offer new advanced preferences that help organize collections and API elements, such as mock server, tests, documentation and monitors generated from API schemas.
Apache JMeter

JMeter was initially built for load testing. The tool provides functionality that lets you run functional API tests. It lets you automate work with CSV files, and quickly produce unique parameter values for tests. It can also integrate with Jenkins, which enables you to include API tests in your CI/CD pipelines. This tool is suitable for running API functional tests as well as performance tests.
Taurus

Taurus provides an automation-friendly framework designed for continuous testing. When used in combination with JMeter, Taurus can handle API testing. The tool can also serve as an abstraction layer on top of other tools, such as Locust, the Grinder, Selenium and Gatling. This level of integration enables teams to adopt performance testing into the CI/CD pipeline.
The main advantage of Taurus is that it lets you write tests in YAML, which is both human-readable and editable. This enables you to describe a test in a simple text file, and even describe a full-blown script in about ten lines of text. Teams can use this functionality to describe their test in a JSON or YAML file.
crAPI
Completely Ridiculous API (crAPI) can help teams understand the ten most important security aspects of an API within a mock environment. crAPI has implemented almost every security loophole that APIs should not have—this offers a good model that showcases how not to secure APIs.
crAPI uses a microservices architecture and is composed of several services which are developed using the following:
- Identity—user and authentication endpoints
- Web:—main Ingress service
- Community -community blogs and comments endpoints
- Mailhog—mail service
- Workshop—vehicle workshop endpoints
- Postgres—SQL Database
- Mongo—NoSQL Database
What to Look For in API Security Testing Tools
Use the following criteria to ensure API security testing tools fit your needs.
- Support for API styles—a critical consideration is whether the tool supports your organization’s API architecture, both current and future. The tool should support REST and GraphQL, if they are in use in your systems. API testing tools should only send the type of requests appropriate to a specific API style, e.g. JSON for REST and GraphQL.
- CI/CD Integration—ensure API security tests can be automated in your pipeline via CI/CD tools, and can run locally to enable easy debugging. This makes it possible to alert developers to vulnerabilities, and allow them to remediate it early in the development process.
- Crawling vs explicit API routes—evaluate whether the tool uses crawling techniques to discover API routes, or leverages standards like OpenAPI (Swagger), Postman or GraphQL introspection to identify API functionality, which is much more accurate.
- Testing speed—the speed at which API tests run can be critical for rapid CI/CD workflows. Tests should take only a few minutes —if they take multiple hours or in some cases days, they can result in productivity issues and break the CI/CD pipeline.
- Developer experience—API security testing tools should be accessible and usable for developers. This makes it possible to shift testing left—ensuring that developers can run tests themselves in their environment and remediate security issues early.If security issues are discovered later on, developers should find it easy to identify and resolve issues. Developer friendly remediation guidelines with a clear proof of concept is therefore paramount.
- False positives—a major concern with any testing tools is the number of false positives. False positive results place a large burden on testing and security teams, because they need to manually inspect and validate every alert. While less of a concern when testing APIs, this is a major factor in your overall appsec testing programme and the tool, which should be able to test both your applications and APIs, needs to minimise false positives, or like with Bright, remove them completely with automatic validation
- Business logic vulnerabilities—APIs are not only vulnerable to security exploits, like injections or other ‘trivial’ attacks.. They may also have gaps or errors in functionality that can create severe logic based security issues, which are typically only tested for manually by security experts. Modern testing tools leverage AI to automatically detect certain business logic vulnerabilities, attempting to bypass the validation mechanisms and logic of the application..
Bright is an automated API security testing tool that provides all these capabilities and more.
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