How to Secure APIs: Best Practices to Follow

Every day, millions of sensitive records pass through APIs, and you know what? Hackers know it. A single weak endpoint can lead to massive data leaks, costly breaches, and irreversible brand damage.

The worst part? API security risks are increasing in both frequency and sophistication, with companies reporting stolen customer data and others having their applications hijacked. Even tech giants have fallen victim, suffered financial losses, regulatory penalties, and a shattered reputation. All this emanates from an overlooked API security flaw.

As a result, learning how to secure APIs is no longer an option—it’s a must. The good news? Securing your APIs doesn’t have to be a nightmare. By implementing proven API security best practices, investing in the right tools, and following a structured security checklist, you can lock down your APIs before hackers strike. 

Read on to learn how to secure your APIs.

Why does API security matter?

What’d happen if you forgot to lock the front door to your house? Securing APIs is essential due to surging cyber threats, stringent compliance and regulatory requirements, and the immense financial and reputational damage that can result from breaches. 

According to research, 95% of organizations have already encountered API security issues, including API vulnerabilities and authentication problems. Here is why you need to learn how to secure your APIs:

Rising cybersecurity threats targeting APIs

As organizations integrate more APIs into their systems, attackers increasingly exploit vulnerabilities such as broken authentication, excessive data exposure, and misconfigurations.

Cyberattacks exploiting APIs have skyrocketed, with recent reports indicating that attacks targeting healthcare and manufacturing have increased by 137%. Without robust protection, APIs can serve as direct entry points for data theft, ransomware, or service disruption.

Compliance and regulatory requirements

APIs often process sensitive data, which is subject to strict data protection laws like GDPR, HIPAA, or local data protection acts. Non-compliance with these requirements can result in serious legal penalties, audits, and loss of customer trust. Following proven API security best practices helps to meet these regulatory standards to avoid consequences for non-compliance.

Mitigating financial and reputational damage

Would your organization survive a million-dollar fine after an API breach?

A single API breach can lead to financial losses, including fines, legal fees, and operational downtime. Beyond monetary costs, when customer data is exposed as a result of a breach, you can suffer reputational damage. Securing APIs can help safeguard both business continuity and trust.

What are the common API security risks?

APIs face a range of security risks that can lead to data breaches, service disruptions, and unauthorized access. Common API security threats include injection attacks, DDoS assaults, inadequate access control, and broken object-level authorization (BOLA). 

1. Injection attacks

Hackers can execute injection attacks by sending malicious input, such as SQL, XML, or command injections, to an API to trick it into executing unintended commands. For example, a poorly sanitized login API might process SQL input as a query, which can expose, modify, or delete sensitive database contents.

2. DDoS attacks

This is one of the prevalent API security risks where attackers overwhelm an API by sending massive traffic from multiple sources, making it unavailable to legitimate users. It’s a common attack that happens on APIs that lack rate limiting or load balancing. 

To mitigate these types of attacks, you need to implement robust strategies such as traffic filtering, IP blocking, cloud-based DDoS protection, and API throttling limits. This will help to detect and block abnormal API request patterns.

3. Lack of access control

Without proper access control, APIs may grant unauthorized users excessive privileges, which can allow them to read, edit, or delete data they shouldn’t access. This often stems from weak authentication or poorly designed role-based permissions. 

Using the best API security tools, such as DigitalAPI, can help to implement strong authentication protocols and well-defined access policies to ensure only permitted users can access specific endpoints.

4. Broken object-level authorization (BOLA)

Without proper access control, APIs may grant unauthorized users excessive privileges, which can allow them to read, edit, or delete data they shouldn’t access. This often stems from weak authentication or poorly designed role-based permissions. 

Using the best API security tools, such as DigitalAPI, can help to implement strong authentication protocols and well-defined access policies to ensure only permitted users can access specific endpoints.

Best practices to secure APIs

Some of the proven best practices for securing APIs include implementing rate limiting, throttling, and strong authentication protocols, using API encryption for data in transit and at rest, implementing role-based access controls (RBAC), and more.

To help you understand what each entails, let’s explore them in depth.

Implement strong authentication protocols

Securing APIs starts with strong authentication to verify user identities to ensure only verified users or systems access your APIs. This involves using protocols like OAuth 2.0, OpenID Connect, or multi-factor authentication (MFA) to prevent unauthorized access. 

To add an extra layer of security to your API keys, you can use token-based authentication (JWT).

Use API encryption for data in transit and at rest

APIs carry millions of sensitive data points that, when they fall into the hands of bad actors, can lead to serious consequences.

API encryption safeguards sensitive information by encoding it so only authorized parties can decode it. 

When transiting data, use TLS/SSL to prevent interception. For data at rest, leverage AES-256 or equivalent encryption algorithms to protect stored information from breaches. This dual-layer approach minimizes risks of data breaches.

Implement rate limiting and throttling.

Rate limiting and throttling are two of the powerful API security best practices for controlling how many requests an API can handle within a given time frame to protect against abuse, denial-of-service (DoS) attacks, and performance issues. 

These measures help maintain API stability and ensure fair usage. 

For effective rate limiting, you can use a robust API management platform like DigitalAPI that offers built-in features for setting granular limits, monitoring traffic, and automatically blocking suspicious activity.

Implement role-based access controls (RBAC)

RBAC is also another proven security best practice that ensures API authorization is based on the principle of least privilege. With role-based access controls, you grant users only the permissions necessary to perform their tasks. 

This prevents unnecessary exposure of API endpoints and minimizes the damage if an account is compromised.

Implement robust authentication and authorization mechanisms

For stronger API security, you need to verify user identity and determine access rights. For this, you need to implement API authentication and authorization mechanisms to ensure that even authenticated users cannot access resources they are not entitled to. 

This involves using API gateways, tokens, and OAuth scopes for fine-grained access control, supported by advanced API security tools.

Tools and technologies for API security

APIs are the backbone of modern digital ecosystems. That’s a plus. But they also introduce significant API security risks. To protect sensitive data and ensure compliance, you need to use robust API security tools and technologies such as DigitalAPI, Burp Suite, Traceable, API gateways, authentication, and authorization technologies.

Let’s explore these in depth.

1. DigitalAPI – AI-powered API management and security 

DigitalAPI stands out as an AI-powered API management platform designed to secure APIs across an organization’s entire ecosystem. It centralizes monitoring, governance, and analytics, ensuring that your entire API ecosystem is visible, compliant, and protected.

From a security standpoint, DigitalAPI offers enterprise-grade protection by integrating automated linting, OWASP checks, and policy enforcement into the development and deployment lifecycle. 

This means API security risks are identified and mitigated early to minimize exposure to vulnerabilities. Automated linting ensures specifications follow proven API security best practices, while OWASP compliance checks guard against top API threats such as injection attacks, broken authentication, and excessive data exposure.

Its policy enforcement engine applies consistent API authorization rules, encryption standards, and access controls across all APIs to ensure uniform compliance with internal and external regulations. 

The platform’s deep analytics capabilities offer you complete visibility into traffic patterns, anomaly detection, and usage trends for proactive threat mitigation.

In addition, DigitalAPI drives API discovery and consumption, making it easier for teams to find and use secure, compliant APIs without compromising performance. Its AI-driven insights optimize API governance and secure APIs at scale. This makes it the preferred choice for organizations that want both powerful management and cutting-edge security in one platform.

Make your API security proactive—not reactive. Book a demo here to see how!

2. Burp Suite – for API penetration testing

Burp Suite is a widely used tool for API penetration testing and vulnerability assessment. It allows both manual and automated scanning to uncover security flaws in APIs, such as misconfigured authentication, injection vulnerabilities, and data exposure. 

Its suite of tools includes intercepting proxies, vulnerability scanners, and fuzzers that simulate real-world attacks. While it is highly effective for identifying weaknesses, you must use it alongside continuous monitoring solutions for ongoing protection.

3. Traceable– for behavioral monitoring and runtime protection

Traceable provides runtime API protection by combining AI-driven behavioral analytics with continuous monitoring. It builds a baseline of normal API interactions and flags deviations that may indicate malicious activity. 

In addition to detecting attacks in real-time, the tool conducts API penetration testing simulations to assess resilience against threats. This makes it a strong option for organizations that require deep runtime insights into API usage patterns.

4. API gateways – for centralized security management

API gateways act as the single entry point for all API traffic to simplify the enforcement of API authorization and security policies. They handle authentication, rate limiting, and request routing, and often include integrated web application firewalls (WAFs) to filter malicious traffic.

Advanced gateways may include bot detection to mitigate automated attacks. While gateways are powerful for traffic control and access management, you need to pair them with dedicated API security tools to handle more sophisticated threats.

5. Authentication and authorization technologies

Strong authentication and authorization mechanisms are essential for securing APIs against unauthorized access. They include:

• OAuth 2.0 & OpenID Connect – These protocols enable secure delegated access and identity verification, ideal for modern API-driven applications.
• JSON Web Tokens (JWTs) – These are compact, digitally signed tokens that carry claims for authentication and API authorization, often used in stateless API communication.
• API keys – API keys are simple credentials for access control, though less secure than token-based methods. They are best used for internal or low-risk APIs with proper rotation and access restrictions.

API security checklist  

Before APIs are released to the end users, they must pass through rigorous checks and testing to ensure they are ready to be used. This requires an API security checklist that goes beyond a simple collection of API security best practices and is based on the API lifecycle.

Use this checklist to secure your APIs.

1. Planning

At the outset, you need to frame API security within your software development life cycle (SDLC). Here, you need to create an inventory of all APIs (including undocumented ones), classifying data sensitivity levels, and assessing associated risks. This foundational work ensures a comprehensive understanding of your API estate and sets the stage for informed security measures.

2. Development

API security needs to be “baked in” during the design and coding phases. Developers should follow secure coding practices, integrate authentication and authorization controls such as API keys and OAuth, ensure input validation, and embed security checks within CI/CD pipelines.

3. Testing

Next, APIs must undergo thorough testing functional, performance, security, fuzzing, penetration, regression, and more. Security testing in particular should be continuous and automated to detect and fix vulnerabilities early and efficiently.

4. Operation and protection

In production, APIs require ongoing discovery, monitoring, and threat prevention. Continuous logging, behavioral analytics, rate-limiting, anomaly detection, and protection against OWASP API Top 10 risks are critical here. 

This phased API security checklist forms a robust, lifecycle-driven security strategy. 

Conclusion

Securing APIs is not a one-time task but an ongoing process that requires vigilance, strong governance, and the right tools. By following proven API security best practices, you can protect your APIs from emerging threats while maintaining performance and reliability. 

However, you need robust API security tools for stronger API security.

The DigitalAPI management platform offers an AI-powered approach to API security, enabling real-time monitoring, deep analytics, and automated threat detection across your entire API ecosystem. 

The platform’s advanced governance features, intelligent risk mitigation, and seamless scalability future-proof your API infrastructure. Why leave your API security to chance? Book a free demo with DigitalAPI today and see how it can transform your API security strategy.

FAQs

1. What is the most effective way to secure APIs?

The most effective way to secure APIs is to combine strong authentication (OAuth 2.0, API keys), TLS encryption, rate limiting, and continuous monitoring. AI-powered API management platforms like DigitalAPI enhance security with threat detection, governance, and analytics to prevent breaches, misuse, and data exposure.

2. How do you protect APIs from unauthorized access?

Protect APIs from unauthorized access by using token-based authentication, role-based access control (RBAC), IP whitelisting, and encrypted connections. You can also use an AI-driven security platform like DigitalAPI for intelligent threat prevention, behavioral analysis, and real-time monitoring to block suspicious activities instantly.

3. What are the top API security tools in 2025?

Top API security tools in 2025 include:

• DigitalAPI – AI-powered API management and security with real-time threat detection.
• Burp Suite – Advanced API penetration testing tool.
• Traceable – Behavioral monitoring and runtime protection against evolving API threats.

4. How does encryption help in API security?

Encryption protects APIs by converting sensitive data into unreadable code during transmission, preventing interception and tampering. TLS/SSL protocols ensure secure connections, while platforms like DigitalAPI integrate encryption with monitoring to detect and block potential attacks.

5. How often should APIs undergo security testing?

APIs should undergo security testing before each major release and at least every quarter. Frequent penetration testing, automated scans, and real-time monitoring with tools like DigitalAPI help identify and fix vulnerabilities before they are exploited.