About the Author
I'm Carrie, the marketing manager of SafeLine WAF. Follow me if you want to learn more about web application firewall.

SafeLine is an open source and self-hosted web application firewall used to protect web applications from various cyber attacks.

In the world of cybersecurity, both Secure Web Gateways (SWG) and Web Application Firewalls (WAF) play crucial roles in protecting digital environments. However, they serve very different purposes, and understanding their distinction is key to designing a strong security architecture.

What is a Secure Web Gateway (SWG)?

A Secure Web Gateway acts as a checkpoint between users and the internet. Its primary job is to protect users from accessing malicious websites, downloading harmful files, or leaking sensitive information.
Key features of a typical SWG include:
• URL filtering
• Malware detection and blocking
• Application control (e.g., blocking certain apps or activities)
• Data Loss Prevention (DLP)
• Enforcing compliance policies (like blocking access to unauthorized content)

In short, SWG focuses on securing outbound traffic — what users inside an organization do when they browse the web.

What is a Web Application Firewall (WAF)?

A Web Application Firewall, on the other hand, protects web applications from external threats.
It monitors, filters, and blocks malicious HTTP/S traffic trying to reach a server or app, focusing on vulnerabilities at the application layer (Layer 7 of the OSI model).

Typical protections a WAF offers include:
• SQL injection prevention
• Cross-Site Scripting (XSS) mitigation
• Bot mitigation
• OWASP Top 10 attack protection
• API security

In short, a WAF focuses on securing inbound traffic — what external users or attackers try to do to your websites and apps.

Key Differences Between SWG and WAF

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Do You Need Both?

In many environments, the answer is yes.
• A SWG protects your users when they are browsing the internet, whether at the office or remotely.
• A WAF protects your digital services, ensuring websites, APIs, and web apps are resilient against attacks.

Together, they form complementary layers of cybersecurity: one guards users, the other guards applications.

Conclusion

Although Secure Web Gateways and Web Application Firewalls might sound similar because they both inspect and filter web traffic, their roles are distinct.

Organizations serious about cybersecurity often deploy both — ensuring that neither users nor applications become easy targets in an increasingly hostile digital world.