Web Filtering for Schools: A Guide

Internet Filtering Software for Schools and Educational Organizations

As schools across the United States continue to embrace digital learning, internet access has become an essential part of the modern classroom. From virtual assignments to online research, the internet offers students a vast and dynamic learning environment. However, this connectivity also brings significant risks, exposing students to harmful content, cybersecurity threats, and digital distractions.

This is where DNS filtering comes into play. DNS (Domain Name System) filtering is a powerful, web security tool that helps schools’ control which websites can be accessed on their networks. By blocking access to malicious, inappropriate, or non-educational content at the network level, DNS filtering plays a crucial role in protecting students, maintaining compliance with federal regulations like CIPA (Children’s Internet Protection Act), and supporting a focused educational experience.

In this article, we’ll explore what DNS filtering is, how it works, and why it’s an essential layer of defense for K-12 schools navigating the digital age.

Why Do Schools Need Web Filtering?

Students and staff need safe and secure internet access to stay productive while working from school, in the library, or at home. In addition to the malicious aspects of insecure internet access, productivity can also suffer. Staff and students with open-ended access to the internet can spend an inordinate amount of time distracted from work-oriented applications, impacting their productivity. Internet-based threats target organizations without web content filters, tricking users into downloading malware or visiting phishing sites. Educational establishments require web content filters to safeguard staff and students' devices, as well as the internal environment, from malware and data breaches.

A report from the Center for Internet Security (CIS) has identified significant increases in threats targeting K-12 schools in the USA. The report is based on 18 months of data across 5000 K-12 schools. The findings conclude the following:

• 82% of K-12 institutions have experienced cyber threats.
• Around 45% of threats target human behavior.
• Attacks surge during exams, disrupting education.

Of great concern is CIS's analysis of attacks. Their analysts found 1 billion connection attempts to malvertisement domains (malicious online ads) and 320 million connection attempts to phishing domains.

A DNS or web content filter provides the necessary protection to prevent cyber-attacks and inappropriate content from disrupting students' education. DNS filters protect students, staff, data, and general educational resources from malicious attacks, including malvertising and phishing sites. They also ensure that students do not view inappropriate or harmful content.

What Types of Web Filters Can Schools Use?

To keep students safe online and create a positive digital learning environment, schools have several web filtering options to choose from. These tools vary in how they work and how much control they provide. DNS filtering blocks dangerous sites before they load; content filtering considers what’s acon a web page to decide whether it’s appropriate; URL filtering lets schools allow or block specific web addresses; and ISP-level filtering applies protections directly through the internet provider.

By understanding the strengths of each approach, schools can choose the right mix to protect students, support acceptable use policies, and keep their networks secure.

DNS Filtering

DNS filtering is a security method that blocks users from accessing malicious or unwanted websites by controlling requests made through the Domain Name System (DNS). When a user types a domain name into a browser, DNS typically resolves it to the corresponding IP address. A DNS filter intercepts this process and checks the requested site against blocklists or policy rules. If the site is flagged as harmful or inappropriate, the request is denied, preventing access before any connection is made.

DNS filtering can apply rules at a granular, per-device level, making it well-suited for environments like schools that need to enforce filtering policies on devices such as Chromebooks.

Advanced DNS filtering solutions, such as WebTitan, enhance this approach using AI and machine learning. These systems analyze large datasets of threats to detect and block new or emerging malicious domains in real time, even before they appear on traditional blocklists.

In short, DNS filtering protects users by stopping dangerous or unwanted websites at the DNS lookup stage, delivering fast, scalable, and proactive web security.

URL Filtering

URL filtering is a web security and content-control technology that determines which websites users can access by evaluating their URLs. When a user tries to visit a site, the URL filter checks the request against a database of categorized URLs and applies policies that either allow or block access to that website.

Each website in the filtering database is assigned to a category, such as adult content, gambling, social media, malware, or phishing. Organizations can use these categories in two main ways:

• Block or allow entire URL categories by creating a filtering profile that specifies which content users can or can’t access.
• Apply policy rules based on URL categories so that only certain types of traffic are affected by specific security or access policies.
• URL filtering relies on either lookups for frequently visited sites or cloud-based databases for the newest or less common URLs. Devices typically cache recently accessed URLs to minimize latency, while cloud queries ensure up-to-date protection.
• URL filtering helps organizations enforce safe browsing and security policies by controlling which websites users can reach based on their URL.

Content Filtering

Content filtering controls and blocks access to websites or online material that is unsafe, inappropriate, or harmful. It is used to stop web-borne threats such as malware, ransomware, and phishing from entering a network and to ensure that users access only content that aligns with business, educational, or organizational policies.

By using content filtering, organizations can prevent users (employees, guests, students, or remote workers) from visiting malicious sites, reduce the risk of data breaches, and enforce acceptable-use standards on both wired and wireless networks.

How Does Content Filtering Work?

Content filtering uses software or hardware solutions that analyze and categorize websites, then apply rules to allow or block access. These systems classify web content such as adult material, gambling, alcohol, social media, or malware using keywords, URLs, and other site characteristics.

When a user attempts to visit a webpage, the content filter:

• Checks the site against categories, policies, blocklists, and threat intelligence
• Blocks access to sites known to host malware, phishing pages, or harmful downloads
• Prevents users from accessing inappropriate or policy-violating content
• Stops malicious files from being downloaded before they reach the network

Content filtering also protects remote users by enforcing the same rules outside the office, ensuring consistent security and reducing exposure to web-borne attacks.Content filtering prevents dangerous or inappropriate online content from reaching users, strengthening cybersecurity while maintaining a safe and compliant browsing environment.

ISP Filtering

ISP filtering is a type of web filtering that is carried out directly by the Internet Service Provider (ISP). The ISP applies filtering rules at the network level before the traffic ever reaches the customer.

How ISP Filtering Works

• The ISP monitors and filters web traffic passing through its own infrastructure.
• It uses blocklists, URL categories, or government-mandated rules to decide which websites should be allowed or blocked.
• Customers receive a pre-filtered internet connection, with specific sites, such as adult content, illegal material, or known malicious domains, restricted automatically.

What if Students Circumvent the Schools Web Filter

Many K12 students make it a daily mission to circumvent the school web filter.  A cat-and-mouse game exists between students and technology staff members; students share the latest public proxy executables to bypass the DNS filter.  Although most school systems have some web filtering, many of these solutions cannot filter mirrored sites, especially those on the scale of large proxy networks.  If a student manages to bypass DNS filter protection, their computer becomes a prime target for ransomware and other types of malware.

TitanHQ prevents DNS filter bypass and audits the internet use of individual students, enabling schools to address student misuse.

Augmenting an Internet Filter with Human-Risk Management

The CIS report on K-12 cyberthreats highlighted the importance of a human-centered and multi-layered approach to school security. The report emphasizes the importance of "empowering the human element" and deploying security awareness training as a key security measure. The report also highlights the need to go beyond awareness training. Human Risk Management (HRM) represents a new era in security awareness training, extending beyond traditional phishing classes. Professor Phil Morgan, Director of the Human Factors Excellence Research Group (HuFEx) at Cardiff University, explains:

"We need human factors and cognitive psychology research to first better understand what human cyber risky behaviors are, to establish why they occur in the first place (and often again and again), and only then can we start to develop effective interventions to support people to exhibit more cyber strengths and far fewer vulnerabilities."

The one-size-fits-all approach to security awareness training is now incorporating behavioral analytics to tailor and optimize training on an individual basis. Human Risk Management measures human cyber behaviors, vulnerabilities, and strengths so that interventions can be developed and tailored to best-fit individuals and groups of similar people. TitanHQ's solutions target behavior to create practical and contextual training that is relevant, positive, and actionable at the time staff or students display risky behaviors. 

Used in conjunction with a DNS filter, HRM creates a security-enhanced learning environment.

What is CIPA, and Why is Compliance Needed?

The CIPA (Children's Internet Protection Act) regulation of 2000 mandates blocking, filtering, and monitoring online content. If an educational institution wants to receive  E-rate funding for Internet access to reduce costs, it must be CIPA compliant.

CIPA requirements can be enforced using DNS filtering solutions for schools, which block malicious websites and filter harmful and inappropriate content. More than ever, schools need to utilize DNS filtering to safeguard their institutions and students.

TitanHQ DNS Filter and Chromebook

Onboarding thousands of students with their Chromebooks requires a significant amount of administrative overhead. Administrators can easily and quickly deploy DNS filtering with new and existing Chromebooks. TitanHQ DNS Filtering integrates directly with your network environment, requiring minimal configuration, making implementation convenient for administrators. Rather than relying on on-premises or installed local client software, TitanHQ DNS Filtering redirects all DNS queries from remote devices to the TitanHQ DNS Filtering cloud system. Using DNS queries, we mitigate the risk of users turning off web filters on their local systems. TitanHQ DNS Filtering identifies and compares the queried domain to several blocklisting factors, including administrator configurations. If the domain is blocklisted, the user is blocked, and a message is displayed informing the user that the domain violates content policies.

Let us show you how TitanHQ DNS Filtering for schools enforces user protection and security while making it convenient for school administrators to manage Chromebook web filtering.

Sign up for a demo today to get started with TitanHQ DNS Filtering.