API Security Buyers’ Guide 2025

State of the market: API security tools protect data that’s exchanged between applications by testing APIs for vulnerabilities that could expose them to attacks such as DoS, DDoS, MitM, access control exploits, and code injections, then notifying your team of the risk.

The API security market was valued at USD 1.05 billion in 2023 and is expected to grow at a CAGR of 29.9% between 2024 and 2032 to reach a value of over USD 11 billion.
Market growth is being driven by a surge in mobile and IoT adoption, which has caused an increase in API usage to facilitate communication between these devices and backend devices.
With more APIs come more vulnerabilities: 90% of developers are currently using APIs and 83% of internet traffic runs through APIs—and all of that data could be compromised if the APIs used contain any vulnerabilities.
- 55% of API requests carry a medium threat level, which is usually caused by design flaws that make them vulnerable to cyberattacks.
- The volume of API data breaches grew 80% between 2022 and 2023, and the number of records breached grew a massive 214% year-on-year.
In light of this, increasingly more development organizations—including SMBs—are adopting API security tools.

Why trust us: We’ve researched, demoed, and tested multiple leading API security solutions, spoken to organizations of all sizes about their integration challenges and the features that are most useful to them, and interviewed executives from leading providers in the AppSec space.

You can find our product reviews, interviews, and Top 10 guides to the best API security products on the market in our DevSecOps Hub.

Our recommendations: Before we get into the details, here are our top tips on how to choose the right API security solution for your business and get the most out of it once deployed:

For easier implementation: Before you even start comparing solutions, try to make an inventory of your current APIs to give you an idea of the scope of the project.
For newer organization: Integrate your API security tool as early on as possible in the development lifecycle—this will make it easier and cheaper to fix any vulnerabilities you discover. This also works for established organizations looking to adopt a “shift left” approach to security.
For best security practice: Adopt a “zero trust” approach to your API security. That means that, rather than automatically trusting all API traffic, you should assume that it’s hostile and enforce strict authentication and encryption measures.
For easier management: Use an API gateway, which will allow you to manage your APIs centrally. This will make it easier to identify and inventory your APIs, as well as implement security across the board.

How API security solutions work: API security solutions are most commonly deployed into the API gateway, though some vendors offer their own control centers.

Once deployed, they create an inventory of all APIs currently in use—including “shadow” APIs (which are created and deployed without the organization’s knowledge), and “zombie” APIs (which are outdated and no longer monitored or maintained).

When this inventory has been created, the API security tool continuously scans each the network traffic of each API for vulnerabilities, as well as applying rate limits to help prevent DDoS attacks, and authenticating API requests to prevent unauthorized access.

When it discovers a vulnerability, the solution notifies you, sending you an alert that includes contextual information to help you respond quickly to the issue. The best tools offer threat prioritization to help you address the most critical issues first according to their severity. Some also offer automated remediation for issues that can be resolved quickly and without human intervention, such as applying readily-available patches.

Benefits of API security solutions: There are four main use cases for implementing an API security tool:

Protect sensitive data
- While using APIs can hugely speed up the development and implementation of new apps, if the API itself hasn’t been designed securely (e.g., lacks proper authentication protocols, is relying on HTTP instead of HTTPS, or isn’t using encryption), a threat actor could exploit its vulnerabilities and access any data being transmitted.
- API security tools help you identify and remediate these types of vulnerabilities, reducing the risk of a threat actor compromising your APIs and stealing your data (and the data of any customers that have installed your app).
Ensure business continuity
- Lots of business-critical applications require APIs to communicate with one another.
- If a threat actor successfully carried out a DoS or DDoS on an API, it can stop genuine users from being able to use it. This can cause widespread issues for anyone relying on that API, e.g., for making banking transactions or booking hospital appointments.
- By using an API security tool, you can reduce the impact of—and downtime caused by—DoS or DDoS attacks, helping to ensure business continuity for your customers in the event your API is targeted.
Ensure compliance with regulatory requirements
- There are numerous data privacy regulations globally that require organizations and individuals to protect sensitive data such as personally identifiable information (GDPR and CCPA), financial information (PCI-DSS), and protected health information (HIPAA).
- Implementing an API security tool can help you comply with these standards by ensuring the security of any data being transmitted between your applications or app components.
Improve customer trust
- If your customers know that you’re actively taking steps to protect their data, they’re likely to feel more confident in using your service and sharing that data with you.

Common API security challenges: There are a few common challenges that you might come across when implementing an API security solution. Here’s what they are and how to overcome them:

API sprawl: It may be challenging for you to identify all the APIs your team is using, particularly if you’re a large organization or have lots of development projects on the go. We recommend using a centralized gateway to help you manage all your APIs in one location. You could also use an API inventory system to help log and classify them.
Third-party API usage: When you’re building an app, you’re likely going to be using lots of third-party APIs, which can lead to further security risks. In this case, make sure you only use APIs from other organizations that implement their own API security practices.
Performance degradation: Adding additional security checks may reduce the response time of your APIs. Though it’s likely to only cause a delay of a few seconds, this can lead to customer frustration. We recommend using API tools that are lightweight and optimized to prevent this from occurring.
Evolving threat landscape: It’s critical that you regularly review the current threat landscape and update your security practices accordingly to offer the best protection you can. You should also look for an API security provider that does this themselves!

Best API security providers: Our team of software analysts and researchers has put together a shortlist of the best providers of API security solutions, as well as adjacent lists covering similar topics:

Features checklist: When comparing API security solutions, Expert Insights recommends looking for the following features:

API discovery: Your tool should automatically discover any APIs your team is using, including zombie and shadow APIs. This process should be continuous, as your team will likely be adding new APIs to new projects regularly.
Authentication: Your solution should verify that the person or service using the API is legitimate by verifying their IP address or authentication token. This can help prevent unauthorized access.
Rate limiting: Your tool should control the number of API requests that can be made within a given timeframe. This can help prevent bots from overloading your APIs with DoS and DDoS attacks.
Encryption: Your tool should encrypt all data in transit.
Real-time monitoring: The tool should log the usage of each API in real-time. You may also want to look for SIEM integration to help you make sense of the dependencies of each API and the impact of their usage.
Integration: You should be able to easily integrate the solution into your DevOps environment to secure APIs during production. Building security into the development process makes it easier and cheaper to fix vulnerabilities than if you were to find them after deploying your app.
Automatic remediation: The best API security tools offer automated remediation for vulnerabilities that are more straightforward to resolve. This will help save your team’s time and resources—though you should still be able to track which risks have been automatically addressed via a centralized dashboard.
Scalability: Your tool should be able to scale easily to secure thousands of APIs across multiple projects, at once. This is particularly important for large and/or growing organizations.
AI integrations: Some API security tools have begun incorporating AI and ML for more accurate traffic monitoring and threat reporting. While not all tools currently offer these capabilities, we expect this to become more commonplace in the near future.

Further reading: You can find all our articles on API security in our DevSecOps Hub.

No time to browse? Here are a few articles we think you’ll enjoy:

Shortlist: The Top 10 API Security Tools
Blog: Expert CISO Advice On Building An Effective DevSecOps Team
Interview: Invicti’s CTO On Finding The Right AppSec Solution
Interview: Glen Pendley On “Left Of Boom” Security And The Inspiration Behind The Tenable One Platform

API Security Buyers’ Guide 2025

How to choose the right API security solution.