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NGINX App Protect vs. Incapsula Imperva WAF vs. open-appsec

Even with the availability of numerous Web Application Firewall (WAF) tools, do you know why choosing one suitable WAF is too difficult of a task to navigate?

It's because it is difficult to find a WAF tool that performs the following:

  • Offers all the necessary web security features

  • Does not increase web latency

  • Can reliably protect against attacks (both known and unknown)

  • Can easily integrate into your app's environment

  • Offers reasonable pricing

Sounds exhausting, right? This article is here to help.

Here, we’ll arm you with all the information you need to make a wise choice between these three web application security solutions: NGINX App Protect, Imperva Incapsula WAF, and open-appsec WAF which is a contemporary WAF that is speedily becoming the people's favorite.

Let’s start by comparing their core features.

NGINX App Protect, Imperva Incapsula WAF, or open-appsec WAF: A Tabular Comparison


NGINX App Protect

Imperva Incapsula WAF

open-appsec WAF

Machine-Learning App Security Approach

Not Available

Not Available

Uses two machine learning models (offline and online) to secure your web apps and web APIs

Type of System Configuration Used

Declarative security policies

WebUI and API

Declarative configuration and WebUI (SaaS)

System Maintenance Complexity

Presence of rules and policies in NGINX App Protect makes it complex to maintain

Runtime Application Self-Protect (RASP) feature prevents automated and real-time attack detection/prevention, and this, in turn, eliminates the need for manual updating and complex system maintenance

Enables effortless system maintenance by eliminating the need for threat signatures, rules, and exceptions to safeguard your web application

Intrusion Prevention System Used

Not Available

Not Available

Snort 3.0 engine

Free Version and Pricing

Offers a 30-day free trial

There’s no free trial, and the pricing plan is divided into four categories:

  1. App Protect Essentials

  2. App Protect Professional

  3. API Enterprise

  4. App Protect 360

Note: you have to contact them for a pricing quotation.

Offers a free and paid version

Free community edition offers free unlimited HTTP Req, while the two paid versions, Premium and Enterprise editions, offer 1M and 100M HTTP Req analysis on a pay-as-you-go basis


Not open-sourced

Not open-sourced

Open-sourced, and an independent group has verified its source code to ensure it's safe and reliable

Malicious Bot Prevention

Uses custom rules and policies to protect against bad bot traffic

Uses bot signatures to prevent bot invasion

Automatically evaluates and improves all previous bot prevention security measures to effectively detect bot traffic

Uses machine learning models to identify malicious bot traffic

Web Latency

Is a lightweight security tool that doesn't increase web latency

Some cases of increased web latency

With the use of agents deploying, open-appsec can be deployed on existing web servers with minimal latency and maximum control

Zero-Day Detection

Doesn’t offer effective protection

Doesn’t offer effective protection

Uses two machine learning models, advanced threat prevention techniques, and the Snort 3.0 Intrusion Prevention System to detect and prevent zero-day attacks effectively

False Positives

Doesn’t detect a lot of false positives

Sometimes it can return a high number of false positives

Reduced cases of false positives because a machine learning model is dedicated to eliminating them

NGINX App Protect

This is the NGINX solution built specifically for web application security. It runs natively on NGINX Plus and can also be deployed with NGINX Plus Ingress Controller, NGINX API Connectivity Manager, or as a service for microservices-based platforms.

It offers two major protection services:

  1. NGINX App Protect WAF

  2. NGINX App Protect DDoS

These two services allow users to use policies, signatures, and exceptions to protect their web apps from layer 7 attacks and the exfiltration stage of the Mitre ATT&ck Framework. Moreover, NGINX App Protect can be used on-premises, in hybrid or multi-cloud environments, on virtual machines, or as a container on microservices platforms.

NGINX App Protect WAF Features

  1. Platform-Agnostic This is its most unique feature. Since it is lightweight, NGINX offers high deployment flexibility and can be used on different distributed architectures and environments, including on-premises, hybrid, multi-cloud, etc. It can also be integrated into Continuous Integration/Continuous Deployment (CI/CD) pipelines to easily automate app security. By using NGINX App Protect and its associated NGINX portfolio of solutions, you'll reduce the complexity of integrations and manage multiple security tools from different vendors.

  2. Apps and API Protection NGINX App Protect offers over 7,500 advanced and bot signatures to protect web apps against OWASP Top 10 attacks. It protects data transfer protocols like HTTP(S), HTTP/2, GraphQL, gRPC, and WebSocket from malicious attacks. Additionally, it effectively protects against DDoS attacks in a cost-effective manner. It does this by constantly evaluating and improving the security measures applied to previous DDoS attacks, reducing the need for manual fine-tuning.

  3. Shift Left for DevSecOps As mentioned earlier, it is lightweight, and that is why it can be incorporated into your app's Software Development Life Cycle. With NGINX App Protect, IT security teams can use declarative security policies to secure a web app without specifying the exact security steps. Furthermore, NGINX App Protect discovers and fixes app vulnerabilities before the app is released; this, in turn, helps save money and time and prevents reputational damages caused by data breaches.

Pros and Cons of NGINX App Protect



Can be deployed in different DevSecOps environments

Uncustomizable anomaly detection system

Less false positives

Has a complex setup procedure

Less web latency

Imperva Incapsula WAF

This on-premises and cloud WAF uses policies, signatures, and exceptions to protect web applications, APIs, and microservices from attacks.

It allows you to create custom rules and policies to detect and manage attack vectors in web requests. They provide a database of policies and allow you to customize and add exceptions as you see fit. For Enterprise customers, you can add policies, custom rules, and exceptions to one or more sites and fine-tune them individually.

Furthermore, Imperva Incapsula WAF offers API security services, bot protection features, content delivery network services, and a reporting and analytics feature that connects with popular SIEM tools. Additionally, it offers 30 to 90 days of data retention, depending on your plan.

Features of Imperva Incapsula WAF

  1. Runtime Application Self-Protect This is a real-time attack detection and prevention feature that monitors all the activity that goes on in an application’s runtime environment. It also monitors an app’s interaction with third-party tools to make a web app less vulnerable to external and injection attacks. It does this by filling out an app’s security gaps and sealing weaknesses like weak cryptography, authentication, browser caching, uncaught exceptions, etc. Additionally, it doesn't require tuning and protects against unvalidated redirects, clickjacking, injections, insider and external threats, and fishes out unknown malicious payloads.

  2. API Security This Imperva Incapsula WAF feature was built to replace the need to track and secure APIs manually. Hence, it automates API protection, eliminates data leakage, and protects API endpoints from abuse. This feature uses machine learning to automate and detect shadow APIs and document and classify API data changes. This automated feature extends to public and private APIs, protecting apps from OWASP Top 10 attacks.

  3. Advanced Bot Protection According to Imperva's 2021 Bad Bot Report, 27% of web traffic comes from bots, and 66.5% comes from evasive bots. As a result, Imperva offers this feature to help you differentiate between human traffic and good and bad bot traffic. Furthermore, it removes bad bot traffic and prevents attacks like online fraud, account takeover, and competitive price scrapping while ensuring the legit user's seamless and uninterrupted experience.

Pros and Cons of Imperva Incapsula WAF



Provides both cloud-based and on-premises options

Reporting and analytics section requires additional columns for tracking app activity

Has an easy-to-navigate user interface

Traffic character limit in the query flags-off legitimate long URL web requests

Offers prompt and dependable customer support, along with round-the-clock hotline accessibility that is available when you're facing a threat

Some of its custom rules can have complex syntax, making them challenging for customers

Effective bot mitigation service

High rate of false positives

open-appsec WAF

Are you looking for a way to block attacks on your web application before they happen? Look no further, as open-appsec uses machine learning to continuously detect and preemptively block threats before they can do any damage. Its code has also been published on GitHub, and the effectiveness of its WAF has been successfully proven in numerous tests by third parties. Try open-appsec in the Playground today.

open-appsec WAF is an open-source tool that protects web applications against malicious requests. Its simplicity of management, flexibility of expansion, and ease of deployment makes it an ideal solution for use in various DevSecOps platforms, including NGINX reverse proxy, k8s Ingress controller, envoy, and API gateways. It also integrates with GraphQL, Terraform, and Helm to foster efficient application operations.

Its unique feature, also highlighted earlier, is its use of machine learning models to defend against OWASP Top 10 attacks, other web app and API attacks, and even zero-day threats.

Moreover, unlike traditional WAFs, open-appsec eliminates the need for signatures and exception handling, thus simplifying WAF maintenance. This is particularly useful in combating rapidly emerging threats and reducing the time and resources traditionally required for WAF upkeep.

Key Features of open-appsec WAF

  1. Machine-Learning Threat Prevention This feature differentiates open-appsec from other WAFs, which conventionally use rules and exceptions to identify malicious activities. In contrast, open-appsec leverages two machine learning models for the preemptive protection of web applications. This proactive stance enables it to counter zero-day attacks like Log4Shell and Spring4Shell without necessitating app updates, signatures, or patches. The first model in open-appsec's machine learning engine is a supervised one that operates offline. It is trained on a massive database of benign and malicious requests, and its function is to discern legitimate traffic from harmful ones. It achieves this by comparing incoming request vectors with the ones in its database and assigning threat scores. It then grants legitimate requests access to the web server, while potentially malicious ones are forwarded to the second model. The second model is unsupervised and operates online in real-time. Its goal is to minimize false positives by verifying the classification of requests forwarded by the supervised model. It analyzes contextual data, user behavior, reputation, and payload scores and permits legitimate requests or blocks malicious ones.

  2. API Discovery and Security This feature aids in identifying all hidden APIs, thereby reducing an app’s attack surface. By applying machine learning-based malicious content blocking and OpenAPI schema validation, open-appsec WAF ensures API activity remains within safe boundaries. This function also enables the security team to focus their resources on a manageable set of APIs, reducing the potential for overlooked vulnerabilities.

  3. Infrastructure-as-Code (IaC) and API This open-appsec feature offers streamlined deployment, updates, and configurations within cloud-native environments. This feature allows the seamless integration of open-appsec into an app's CI/CD process by leveraging the concept of IaC or APIs. Additionally, open-appsec WAF provides flexible management options. Users can configure and control open-appsec through declarative configuration files that are also compatible with config files, Kubernetes, and cloud-native configuration-as-code, as well as annotations. Alternatively, open-appsec supports WebUI-Based Configuration, which leverages the GraphQL API and provides features such as central status monitoring for agents and cloud-based log storage.

Pros and Cons of open-appsec WAF



Simplifies system upkeep by eliminating exception handling, rules, policies, and threat signatures

A fairly new WAF

Effectively protects against zero-day attacks

Has a medium-sized open-source community


Effectively hardens an app’s attack surface

Has a free version

Offers 24/7 customer support in its paid version


NGINX App Protect is best for organizations that manage multiple apps, and it can be easily integrated into different DevSecOps environments. Imperva Incapsula WAF is best known for its advanced bot protection feature. Finally, open-appsec is popular for detecting and preventing zero-day attacks. Try open-appsec in the Playground today.

Frequently Asked Questions

What is the difference between ModSecurity and NGINX App Protect?

ModSecurity is an open-source WAF that is compatible with various web servers and provides robust protection against attacks. On the other hand, NGINX App Protect is a commercial WAF that offers advanced web app security features like API security, behavioral DoS protection, etc.

Is NGINX a Web Application Firewall?

No, NGINX is not a Web Application Firewall (WAF). It is a web, reverse proxy, load balancer, and HTTP cache. However, NGINX can be used with a WAF like ModSecurity or NGINX's own commercial WAF, or NGINX App Protect for web app security.

Is NGINX Plus free?

No, NGINX Plus is not free, although it offers a free trial. It is a commercial product offered by F5 Networks and provides additional features beyond the open-source version of NGINX.

Is Incapsula the same as Imperva?

Yes, Incapsula is the same as Imperva. They were initially two distinct companies, but in February 2014, Imperva bought Incapsula, making them the same company.


Experiment with open-appsec for Linux, Kubernetes or Kong using a free virtual lab

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