Technical Review by
Craig MacAlpine
DNS web filtering platforms block access to malicious and policy-violating websites at the DNS resolution layer — before connections are established — providing threat protection and acceptable use enforcement that applies to all devices, including those without endpoint agents. DNS-layer filtering stops threats before any content reaches the device. We reviewed the top platforms and found ThreatLocker Web Control, Avast Secure Internet Gateway, and Barracuda Content Shield to be the strongest on classification accuracy and off-network enforcement.
Web security should be a top priority for your organization. Malicious websites can give hackers access to your private data, so keeping employees safe online is important. One of the most effective ways to protect against web-based threats is DNS filtering. These platforms block dangerous websites at the DNS layer, before any content reaches the endpoint.
To help you find the right product, here’s Expert Insights’ list of the top DNS Web Filtering platforms. We’ll discuss their effectiveness at web filtering, the threat protection they offer, the quality of reporting, and how easy they are to deploy.
1. ThreatLocker Web Control
2. Avast Secure Internet Gateway
3. Barracuda Content Shield
4. Cisco Umbrella
5. Cloudflare Gateway
6. DNSFilter
7. NordLayer DNS Filtering
8. Palo Alto Networks DNS Security
9. TitanHQ, powered by CyberSentriq
10. Webroot DNS Protection
11. Zscaler DNS Security
ThreatLocker Web Control is a web filtering solution within the ThreatLocker Zero Trust Endpoint Protection Platform. It provides access control and phishing protection without relying on traditional DNS filtering, avoiding the error pages and certificate issues that come with DNS-based approaches.
ThreatLocker Web Control uses dynamically updated libraries of prohibited websites across customizable categories, blocking phishing and malicious sites using millions of data points. Agent or agentless deployment options provide flexibility, with a browser extension for permission requests on blocked sites. Policies apply to unmanaged devices on the network through DNS, reducing risks across the full environment. A company-managed block page improves the user experience, and unified audit logs track blocked website requests to support GDPR, HIPAA, and PCI DSS compliance.
We rate ThreatLocker Web Control highly for its unified integration within the wider ThreatLocker platform and the flexibility of agentless deployment. The platform is a strong fit for businesses looking for an integrated, easy-to-deploy web filtering solution that secures web access and protects against phishing across all devices. A 30-day trial is available.
Avast Secure Internet Gateway (SIG) is a cloud-based unified threat management platform designed to replace on-premises security appliances for SMBs and MSPs. We think the core appeal is the full SSL/TLS inspection capability; most web threats now hide inside encrypted traffic, and SIG can actually inspect it.
The standout capability is full SSL/TLS inspection across encrypted traffic. SIG can decrypt, inspect, and re-encrypt HTTPS sessions to catch threats that DNS-only filtering would miss entirely. The platform blocks malicious downloads and known malicious URLs using an intelligent proxy to classify sites as safe or unsafe. Admins can monitor web traffic in real time, with visibility and reporting that help detect and filter threats. Policies follow users regardless of location, which is strong for remote workforces.
MSP partners praise the centralized management through CloudCare, particularly for multi-tenant environments where managing separate appliances per client isn’t practical. Avast is designed for use by small security teams and organizations, with a focus on ease of deployment. The gateway can be deployed within minutes. Something to be aware of is that SIG is only available through Avast CloudCare partners, not as a direct purchase.
We think Avast SIG works best for MSPs managing SMB clients through CloudCare who need web security without deploying hardware. The SSL/TLS inspection is a real differentiator at this price point. If you’re not already in the CloudCare partner program, the indirect purchasing model may be a barrier.
Barracuda Content Shield is a DNS filtering and web content protection platform designed for SMBs and MSPs. The platform classifies domains into 85 categories using machine learning and incorporates government blacklists for high-risk sites. We should note upfront: Barracuda has discontinued Content Shield, so while we’ve included it for reference, it’s no longer available for new deployments.
Content Shield offers two filtering approaches. DNS filtering applies a blanket policy to an entire network based on egress IP address, covering all devices without installing an agent. For more granular control, the Web Filtering Component (WFC) uses a lightweight endpoint agent to enforce per-user policies across browsers and applications. Content Shield provides real-time protection against online threats, powered by Barracuda’s threat intelligence network. It protects users against downloaded files, endpoint files, and malicious web content.
Customers who used the platform praised the dual DNS and agent-based filtering approach for balancing simplicity with fine-grained control. The 85-category classification system was well-regarded for accuracy. One of the main benefits was the ease of setup and deployment, with users reporting the platform was easy to use with strong visibility into web-based threats. With that said, the product has been discontinued, and customers note uncertainty around migration paths.
Barracuda Content Shield had a solid feature set, particularly the dual DNS and agent-based filtering model. But with the product discontinued, we can’t recommend it for new deployments. If you’re an existing Content Shield customer, we’d suggest reaching out to Barracuda about migration options.
Cisco Umbrella is one of the most widely deployed DNS security platforms on the market. It resolves over 620 billion DNS requests daily and uses that volume to build real-time threat intelligence that feeds directly into its filtering engine. We think the scale of the threat intelligence is the key differentiator here. Cisco filters billions of webpages and carries out advanced research into threat protection, which has greatly increased the effectiveness of their filtering.
Umbrella blocks threats at the DNS layer before a connection is ever established, which means malware, ransomware, and phishing domains are stopped before any content reaches the endpoint. The platform includes a secure web gateway, cloud-delivered firewall, and CASB in higher-tier packages. An intelligent proxy adds deeper inspection for risky domains without slowing safe traffic. The Investigate console provides deep threat intelligence with domain risk scoring, real-time DNS query data, and historical analysis.
Customers consistently praise the speed of deployment; pointing DNS to Umbrella’s resolvers takes minutes and provides immediate protection. The platform is powerful and well liked by customers. It’s easy to install and deploy. The Investigate console gets strong feedback from security teams who use it for incident response and threat hunting. Something to be aware of is that Cisco is transitioning Umbrella into Cisco Secure Access, so buyers should confirm the migration roadmap.
We think Cisco Umbrella remains one of the strongest DNS security platforms available, particularly for organizations that want DNS-layer protection backed by large-scale threat intelligence. The Investigate console is a real differentiator for security teams doing active threat hunting. We’d recommend it to organizations who don’t mind paying a higher cost for an easy-to-use and trusted filtering service. Advanced SWG, CASB, and firewall features are locked to higher-tier licenses.
Cloudflare Gateway is the DNS filtering and secure web gateway component of Cloudflare One, Cloudflare’s SASE platform. We think the performance advantage is the real story here; Cloudflare operates one of the fastest global networks with data centers in over 310 cities. Cloudflare is known for their DDoS and consumer DNS protection, and from those platforms they see millions of DNS lookups, data which is unparalleled among some other vendors in the DNS protection space.
Gateway filters DNS, HTTP, and network traffic through a single policy engine. DNS filtering blocks malicious domains and enforces content categories at the resolver level. HTTP filtering adds deeper inspection with identity-aware policies, file type controls, and tenant isolation. Shadow IT discovery identifies unauthorized SaaS applications being used across the organization. Remote browser isolation is available as an add-on for high-risk browsing.
Customers highlight the speed and reliability of DNS resolution, which is consistent with Cloudflare’s broader network performance reputation. The integration with Cloudflare Access and Zero Trust is well-regarded by teams already using Cloudflare’s broader platform. Something to be aware of is that full policy control requires deploying the WARP client to endpoints.
We think Cloudflare Gateway is best suited for organizations that want DNS filtering as part of a broader Zero Trust architecture rather than as a standalone tool. The multi-layer filtering across DNS, HTTP, and network traffic is really strong. If your team is already in the Cloudflare stack, Gateway integrates naturally. For teams new to Cloudflare, the admin console has a learning curve.
DNSFilter is a cloud-based DNS filtering platform built around AI-powered domain categorization. We think the speed of threat detection is the core differentiator; DNSFilter uses machine learning to classify domains in real time rather than relying solely on static blocklists. It’s a flexible service, driven by API, and offers strong protection against web-based threats.
The AI categorization engine is the standout feature. It analyzes domain characteristics in real time to classify threats, which means protection extends to domains that are minutes old rather than waiting for human analysts to add them to blocklists. DNS PreCheck protects roaming users on unmanaged networks, while CyberSight adds behavioral analytics and threat intelligence visibility. The multi-tenant dashboard is well-suited to MSP environments with per-client policy management.
Customers praise the deployment speed; filtering can be active within minutes of pointing DNS to DNSFilter’s resolvers. MSPs highlight the multi-tenant dashboard and per-client policy management as strong points. The service is noted for being cost-effective with an excellent user experience. Something to be aware of is that DNSFilter is DNS-layer only, with no SWG or full proxy capabilities.
We think DNSFilter is one of the strongest pure DNS filtering platforms on the market. The AI-powered categorization gives it a real speed advantage over list-based alternatives, and the 2026 additions of DNS PreCheck and CyberSight show active product development. It’s a good option for smaller organizations, MSPs, and teams looking for strong protection at a competitive price. If you need full web proxy or content inspection beyond DNS, you’ll need to pair it with an SWG.
NordLayer DNS Filtering is a DNS-layer security feature built into NordLayer’s business VPN and network access platform, developed by Nord Security. We think the appeal is the simplicity; NordLayer targets organizations that want DNS filtering without deploying a separate product or managing a new vendor.
DNS filtering is available from the Core plan upward and blocks access to malicious domains, phishing sites, cryptojacking, and adult content by category. The threat intelligence feeds come from multiple sources and are updated continuously using machine learning classification. Centralized policy management lets admins apply organization-wide or group-specific filtering rules. The platform activates in under 30 seconds with minimal configuration.
Customers praise the ease of setup and the clean, easy-to-navigate dashboard. Teams with limited IT resources appreciate that filtering doesn’t require deep technical knowledge to configure. Something to be aware of is that NordLayer’s DNS filtering is relatively basic compared to dedicated DNS security platforms on this list.
We think NordLayer DNS Filtering is best suited for organizations that already use NordLayer for VPN and network access and want DNS filtering as an added layer. It’s not a replacement for dedicated DNS filtering platforms if you need advanced reporting, custom categories, or granular per-user controls. But for teams that want one vendor covering VPN and basic DNS protection, it’s a practical addition.
Palo Alto Networks Advanced DNS Security is a cloud-based DNS protection service powered by Precision AI that integrates directly with Palo Alto’s firewalls. We think this is one of the most technically advanced DNS security products on the market, with predictive AI capabilities that detect malicious domains before they appear on traditional blocklists.
The platform detects and blocks DNS tunneling, command-and-control traffic, domain generation algorithms (DGAs), and newly registered domains. Threat intelligence feeds are shared across Palo Alto’s customer base in real time, which means a threat identified for one customer is immediately blocked for all. Centralized Panorama management enforces consistent DNS policies across locations. The 2026 updates add IPv6 support and custom sinkhole configurations.
Customers in large enterprise environments praise the integration with Palo Alto firewalls and Strata Cloud Manager. Security teams highlight the DGA detection and DNS tunneling prevention as strong capabilities. Something to be aware of is that Advanced DNS Security requires a Palo Alto NGFW or Prisma Access deployment; it isn’t available as a standalone product.
We think Palo Alto Advanced DNS Security is a very strong choice for organizations running Palo Alto firewalls that want DNS-layer threat prevention integrated into their existing security stack. The predictive AI capabilities and real-time threat sharing across the customer base are real differentiators. If you’re not in the Palo Alto stack, the dependency on their firewalls makes it impractical.
WebTitan DNS Filter by TitanHQ is a DNS-based web filtering solution that provides threat protection and advanced content filtering controls. The platform filters over 500 million URLs and offers a comprehensive policy engine for granular content filtering rules and categories. WebTitan provides protection against malicious webpages, phishing, viruses, ransomware, and harmful web content, making it a strong solution for SMBs, MSPs, and schools.
WebTitan provides content filtering to stop users from accessing malicious or harmful web pages and ensures compliance with legal standards. AI-powered threat protection engines identify zero-day phishing domains and malicious URLs. The service offers remote management and monitoring via API with no latency, allowing admins to configure granular policies and generate reports from any location.
WebTitan is a strong solution for education environments, allowing admins to configure policies to protect students and ensure compliance standards are met. The platform is popular in the MSP community, providing margin-friendly pricing and API-based deployment. WebTitan is scalable, fast, and affordable, with DNS-based filtering that requires no on-premises hardware.
We think WebTitan DNS Filter is one of the strongest DNS filtering platforms for MSPs serving SMB clients and for education environments. The granular policy engine, AI-powered zero-day threat detection, and margin-friendly MSP pricing make it a practical choice for service providers. If you need full web proxy inspection or advanced analytics beyond DNS filtering, you will need to pair WebTitan with an SWG.
Webroot DNS Protection, now part of OpenText’s cybersecurity portfolio as OpenText Core DNS Protection, is a cloud-based DNS filtering platform that provides threat blocking and content filtering at the DNS layer. We think the integration with Webroot’s endpoint security console is the key selling point here. Webroot offers a fast, light, and easy-to-manage service that’s popular with MSPs.
The platform filters every DNS request from browsers, applications, and background processes, blocking threats before they reach the network or device. Content filtering covers over 80 URL categories with granular policy-based controls by group, device, or location. DNS over HTTPS (DoH) support is included, and the platform recently migrated to Google Cloud Platform for improved reliability. It’s easy for clients currently using Webroot Endpoint Protection to upgrade to this service.
Customers praise the ease of deployment and the integration with Webroot’s endpoint console. MSPs managing multiple clients highlight the centralized management and per-client policy controls. The service is popular with MSPs because of how easy it is to deploy and how little support it needs once set up. Something to be aware of is that the product has been rebranded to OpenText Core DNS Protection, and some customers note licensing confusion during the transition.
We think Webroot DNS Protection is a solid choice for organizations already using Webroot endpoint security or MSPs managing clients through the Webroot console. The DoH support and IPv6 compatibility keep it current. We recommend this service as a low-cost but high-quality option, particularly for MSPs and smaller teams who want DNS filtering that works well alongside Webroot endpoint protection. If you need advanced analytics or deep content inspection, dedicated DNS platforms offer more.
Zscaler DNS Security is the DNS filtering component of Zscaler Internet Access (ZIA), delivered through Zscaler’s cloud-native proxy architecture across more than 150 edge locations globally. We think the inline inspection model is what sets this apart from basic DNS filtering; Zscaler inspects DNS traffic inline rather than just filtering at the resolver level.
The platform encrypts plaintext DNS traffic into DNS over HTTPS (DoH) to prevent eavesdropping and tampering, with the ability to detect and stop attacks that try to hide inside DoH traffic. DNS tunnel detection identifies data exfiltration attempts that bypass traditional filters. DGA blocking catches domains generated by malware for command-and-control communication. The service meets Protective DNS compliance requirements from NSA, CISA, and NCSC.
Enterprise customers praise the integration with ZIA and the broader Zscaler Zero Trust Exchange. Security teams highlight the DNS tunnel detection as particularly effective for preventing data exfiltration. Something to be aware of is that Zscaler DNS Security requires a Zscaler ZIA deployment; it isn’t available as standalone DNS filtering.
We think Zscaler DNS Security is one of the strongest DNS protection layers available for organizations already running or planning to deploy Zscaler ZIA. The inline DNS inspection, tunnel detection, and DoH encryption are really advanced capabilities. If you’re building a Zscaler-based security stack, DNS Security is a natural addition. For organizations that only need DNS filtering, the ZIA dependency and pricing make standalone alternatives more practical.
DNS filtering is the process of filtering web content at the DNS level. With a DNS filter in place, when an end user loads a website, the DNS query is sent to a DNS resolver, using the filtering service. If the web domain is on a blocklist, or contains malicious content, the DNS filtering service will tell the resolver to block the request, preventing a malicious webpage from loading and protecting the user from unsafe content.
DNS filtering can be used to protect employees from harmful and inappropriate web content by enabling admins to enforce policies around which categories of web content is acceptable and not. DNS security tools can also be used to enforce broader network security policies protecting against DNS-based malware attacks.
Phishing is an important use case for DNS filtering. Phishing emails often use links to malicious web pages, such as a fake landing page, in order to steal credentials. With a DNS filter in place, when an end user clicks a harmful link, the phishing website domain is blocked and the user protected against phishing threats.
DNS filtering uses the DNS lookup process to filter access to web content for users connected to the DNS Filtering system. DNS filtering services can either filter web content by domain name or by IP address. When filtering by domain name, the DNS process doesn’t take place at all for certain domains. When filtering by IP address, the DNS system resolves the IP address and domain name, but access to the resolved domain is blocked for the user requesting the lookup.
In practice for a user, both methods have the same result. When you look up a blocked domain name, instead of being taken to the webpage, you are taken to a page hosted by the DNS filter. This page should explain that the webpage you have requested has been blocked for being unsafe or inappropriate.
DNS filtering services build block lists of harmful domains or IP addresses, known as blocklists or denylists. These can be shared across providers or built as proprietary lists based on threat intelligence and threat research. The bigger the database of threat research, the more comprehensive the blocklist is likely to be. These blocklists are primarily used to classify malicious domains – sometimes in real time- but they are also used to classify safe web content into categories, such as “Social Media”. Using the DNS filtering service, admins can block access to certain types of safe content in order to enforce company safe usage policies, for example, blocking access to adult material, gambling sites, etc.
If you’re considering investing in a DNS filtering solution, there are a number of important features to look for:
Joel is the Director of Content and a co-founder at Expert Insights; a rapidly growing media company focussed on covering cybersecurity solutions.
He’s an experienced journalist and editor with 8 years’ experience covering the cybersecurity space. He’s reviewed hundreds of cybersecurity solutions, interviewed hundreds of industry experts and produced dozens of industry reports read by thousands of CISOs and security professionals in topics like IAM, MFA, zero trust, email security, DevSecOps and more.
He also hosts the Expert Insights Podcast and co-writes the weekly newsletter, Decrypted. Joel is driven to share his team’s expertise with cybersecurity leaders to help them create more secure business foundations.
Craig MacAlpine is CEO and Founder of Expert Insights. Before founding Expert Insights in August 2018, Craig spent 10 years as CEO of EPA Cloud, an email security provider that rebranded as VIPRE Email Security following its acquisition by Ziff Davis, formerly J2Global (NASDAQ: ZD) in 2013.
Craig is a passionate security innovator with over 20 years of experience helping organizations to stay secure with cutting-edge information security and cybersecurity solutions.
Using his extensive experience in the email security industry, he founded Expert Insights with the singular goal of helping IT professionals and CISOs to cut through the noise and find the right cybersecurity solutions they need to protect their organizations.