DNS Speed Test

How DNS Protects You

Most people think of DNS as a simple phonebook — you type a name, it returns an address. But a security-focused DNS resolver does far more than translate domain names. It acts as the first line of defense between your device and the threats hiding across the internet.

Every time you click a link, open an email, or load a webpage, your device sends a DNS query to resolve the target domain. If that domain points to a known phishing page, a malware distribution server, or a command-and-control endpoint, a security DNS resolver can block the connection before it is ever established. Your device never contacts the malicious server. The threat is neutralized at the DNS level, before any data is exchanged.

This approach works because threats need DNS to function. Malware authors register domains for C2 servers, phishing campaigns use lookalike domains, and ransomware operators host decryption key exchanges on their own infrastructure. All of these require DNS resolution. By intercepting and filtering DNS queries, security resolvers eliminate the infrastructure that attackers depend on.

The speed advantage of DNS-level protection is significant. Traditional antivirus software scans files after they are downloaded, which means the malicious payload is already on your device. DNS blocking prevents the download from happening in the first place. There is no file to scan, no quarantine to manage, and no risk of a false negative slipping through.

DNS-level security also covers every device on your network. When you configure a security DNS resolver at the router level, every connected device — phones, tablets, smart TVs, IoT gadgets — benefits from the same protection. This is especially valuable for devices that cannot run traditional antivirus software, like smart home devices, gaming consoles, and connected appliances that frequently communicate with external servers.

The limitation is that DNS blocking only works against known threats. If a domain is new and has not yet been flagged by threat intelligence feeds, it will not be blocked. This is why the quality and freshness of a provider's threat intelligence matters so much — the best providers update their blocklists continuously, drawing from dozens of sources to minimize the window between a threat appearing and being blocked.

What Makes a DNS Server Secure

Not all DNS providers that advertise "security" deliver meaningful protection. A genuinely secure DNS server requires multiple components working together, each addressing a different threat vector.

Malware Blocking

A secure DNS resolver maintains a blocklist of domains associated with malware distribution, botnet command-and-control, and exploit kits. When your device tries to resolve a domain on the blocklist, the resolver returns a null response or redirects to a warning page instead of the actual IP address. The quality of malware blocking depends on the breadth and freshness of the threat intelligence feeds the provider uses. Quad9, for example, draws from over 25 sources including IBM X-Force, Proofpoint, and CrowdStrike, updating its blocklist multiple times per day.

Phishing Protection

Phishing domains are designed to look identical to legitimate sites — a fake banking page, a counterfeit login portal, a spoofed corporate website. DNS-level phishing protection identifies these domains through a combination of brand impersonation detection, certificate analysis, and URL pattern matching. The best providers flag newly registered domains that mimic known brands, which is where the majority of phishing attacks originate. OpenDNS and Cisco Umbrella are particularly strong here because Cisco's Talos Intelligence team has deep visibility into phishing infrastructure across the globe.

DNSSEC Validation

DNSSEC (Domain Name System Security Extensions) adds cryptographic verification to DNS responses. Without DNSSEC, your device has no way to verify that the DNS response it received was not modified in transit. An attacker can perform a man-in-the-middle attack, intercept your DNS query, and return a fake IP address pointing to a malicious server — all without your browser showing any warning. DNSSEC prevents this by signing DNS records with cryptographic keys that can be verified at each step of the resolution chain. A secure DNS resolver should enforce DNSSEC validation by default, rejecting any response that cannot be verified. Quad9 and Cloudflare both enforce DNSSEC.

Threat Intelligence Feeds

The underlying threat intelligence determines how effective a security DNS provider actually is. The best providers combine multiple data sources: commercial threat feeds (IBM X-Force, Cisco Talos, Symantec), open-source intelligence (OpenPhish, PhishTank, URLhaus), honeypot networks that collect real-time malware samples, and partnerships with security research institutions. A provider that relies on a single source has blind spots. The best providers cross-reference multiple feeds to reduce false positives and catch threats that individual sources might miss.

Encrypted Transport

A DNS resolver cannot protect you if your queries can be intercepted and manipulated before they reach the resolver. DNS over HTTPS (DoH) and DNS over TLS (DoT) encrypt your queries so that your ISP, network operator, or any intermediary cannot read or modify them. Encrypted transport also prevents DNS-based censorship and throttling. Every provider in this guide supports DoH and DoT, and several support DNS over QUIC (DoQ) for even better performance.

Top 5 DNS Servers for Security in 2026

These five providers combine robust threat blocking, DNSSEC enforcement, and strong threat intelligence. Each has been evaluated on blocking effectiveness, threat feed quality, DNSSEC support, and encryption options.

#1 — Quad9 (9.9.9.9)

Threat blocking: Malware, phishing, exploit kits | DNSSEC: Enforced | Encryption: DoH, DoT, DoQ | Cost: Free

Quad9 is the gold standard for DNS security. Operated by a Swiss nonprofit, it blocks known-malicious domains by default using threat intelligence from over 25 sources — IBM X-Force, Proofpoint, CrowdStrike, VirusTotal, and dozens more. The blocklist updates multiple times daily, which means newly discovered threats are caught within hours rather than days.

What sets Quad9 apart is that security is its primary mission. Unlike providers that treat security as an optional feature, Quad9 was built from the ground up as a security resolver. DNSSEC validation is enforced by default — responses that fail cryptographic verification are rejected. This protects against DNS spoofing, cache poisoning, and man-in-the-middle attacks that target DNS.

Quad9 is headquartered in Switzerland, outside all major intelligence alliances, and does not log IP addresses or user-identifiable data. The nonprofit structure means there is no commercial incentive to weaken security features. For users who want security as the default, not an opt-in setting, Quad9 is the strongest choice available.

IPs: 9.9.9.9, 149.112.112.112 | DoH: https://dns.quad9.net/dns-query | DoT: dns.quad9.net

Visit Quad9 · How to set up

#2 — Cloudflare for Families (1.1.1.3)

Threat blocking: Malware + adult content | DNSSEC: Enforced | Encryption: DoH, DoT | Cost: Free

Cloudflare offers three DNS variants: 1.1.1.1 (unfiltered), 1.0.0.3 (malware blocking only), and 1.1.1.3 (malware + adult content blocking). The 1.1.1.3 variant is the security-focused option, blocking domains associated with malware, phishing, and ransomware while also filtering adult content for families.

Cloudflare's security blocking is backed by its massive network — resolver nodes in over 300 cities across 100+ countries, all connected to their anycast infrastructure. Threat intelligence comes from Cloudflare's own research team and partnerships with security organizations. The company engages KPMG to audit its privacy practices annually, confirming that query logs are purged within 24 hours.

DNSSEC is enforced on all Cloudflare DNS variants. The 1.1.1.3 resolver validates DNSSEC signatures and rejects tampered responses. For users who want both speed and security, the family variant provides meaningful threat blocking without the performance penalty — Cloudflare 1.1.1.3 is still one of the fastest DNS resolvers in the world.

IPs: 1.1.1.3, 1.0.0.3 | DoH: https://family.cloudflare-dns.com/dns-query | DoT: family.cloudflare-dns.com

Visit 1.1.1.1 · How to set up

#3 — OpenDNS FamilyShield

Threat blocking: Malware, phishing, adult content | DNSSEC: Supported | Encryption: DoH | Cost: Free

OpenDNS FamilyShield is operated by Cisco, one of the largest cybersecurity companies in the world. It uses Cisco Umbrella's threat intelligence — sourced from Talos Intelligence, one of the most comprehensive threat research teams in the industry. FamilyShield blocks domains associated with malware, phishing, botnets, and adult content, making it a strong choice for both security and parental controls.

Cisco Talos analyzes over 600 billion DNS requests daily, giving them extraordinary visibility into global threat activity. When a new phishing campaign or malware distribution network is identified, the blocklist is updated across OpenDNS infrastructure within minutes. This scale of threat intelligence is difficult for smaller providers to match.

OpenDNS also offers a paid Umbrella tier for businesses that adds detailed reporting, security analytics, and policy management. For home users, FamilyShield is free and requires no registration — just change your DNS settings to 208.67.222.123 and 208.67.220.123.

IPs: 208.67.222.123, 208.67.220.123 | DoH: https://family.opendns.com/dns-query

Visit OpenDNS · How to set up

#4 — AdGuard DNS

Threat blocking: Malware, phishing, ads, trackers | DNSSEC: Supported | Encryption: DoH, DoT, DoQ | Cost: Free (300K queries/mo)

AdGuard DNS combines security protection with ad and tracker blocking in a single resolver. It blocks known phishing domains, malware distribution sites, and spyware command-and-control servers while simultaneously stripping out advertisements and tracking pixels. The dual protection makes it particularly effective for users who want a clean, safe browsing experience without installing multiple extensions.

AdGuard maintains its own threat intelligence database, updated regularly with data from community reports and security research. The service offers three variants: standard (ads, trackers, and malware blocked), family (adds adult content blocking), and non-filtering (no blocking, just fast resolution). For security, the standard server at 94.140.14.14 is the right choice.

The free tier includes 300,000 queries per month, which covers most individual users. The paid plan removes the query limit and adds access to dedicated servers. AdGuard supports DoH, DoT, and DoQ, giving you the widest range of encryption options among the providers in this guide.

IPs: 94.140.14.14, 94.140.15.15 | DoH: https://dns.adguard-dns.com/dns-query

Visit AdGuard DNS · How to set up

#5 — Norton ConnectSafe

Threat blocking: Malware, phishing, scams | DNSSEC: Supported | Encryption: DoH | Cost: Free (limited queries)

Norton ConnectSafe leverages Symantec's threat intelligence — one of the longest-running and most widely deployed security databases in the world. Symantec's Global Intelligence Network processes billions of security events daily, providing ConnectSafe with real-time threat data on malware, phishing, and scam domains.

ConnectSafe offers three policy levels: security-only (malware and phishing), privacy (adds tracker blocking), and parental (adds adult content filtering). The security policy at 199.85.126.10 and 199.85.127.10 is the right choice for users focused purely on threat protection.

The main limitation of Norton ConnectSafe is its query limit on the free tier, which restricts heavy users. For households with many devices, the limit can be reached quickly. However, for individual users or small households, the Symantec threat intelligence backing makes ConnectSafe a solid security choice. The service supports DNS over HTTPS for encrypted transport.

IPs: 199.85.126.10, 199.85.127.10 | DoH: https://connectsafe.norton.com/dns-query

Visit Norton ConnectSafe · How to set up

DNSSEC Explained

DNSSEC (Domain Name System Security Extensions) is a set of cryptographic protocols that add authentication to DNS. It does not encrypt your queries — that is what DoH and DoT are for — but it verifies that the answers your device receives have not been tampered with.

How DNSSEC Works

When a DNSSEC-enabled resolver looks up a domain, it follows a chain of trust from the root zone down to the specific domain. Each level in the chain — root, TLD, authoritative server — signs its responses with a cryptographic key. The resolver verifies each signature against the parent zone's public key. If any signature in the chain is missing, invalid, or does not match, the resolver rejects the response.

This prevents several classes of attacks. DNS spoofing, where an attacker forges a DNS response to redirect you to a malicious server, is blocked because the forged response will not have a valid signature. Cache poisoning, where an attacker injects fake DNS records into a resolver's cache, is prevented because the resolver will reject unsigned records. Man-in-the-middle attacks that modify DNS responses in transit are detected because the signatures will not match.

Why DNSSEC Matters

Without DNSSEC, your device has no way to verify the authenticity of a DNS response. You are trusting that the response came from the legitimate authoritative server and was not modified along the way. On a trusted home network, this is usually fine. On public Wi-Fi, corporate networks, or any environment where an attacker could intercept traffic, the lack of DNSSEC is a real vulnerability.

DNSSEC is also a prerequisite for DNS-based encryption to provide full protection. DoH and DoT encrypt your query so no one can see what you are looking up, but without DNSSEC, the encrypted response could still be forged. The combination of encrypted transport and DNSSEC validation gives you both privacy and authenticity.

Which Providers Support DNSSEC

DNSSEC support varies among major providers. Quad9 and Cloudflare enforce DNSSEC by default — they will reject responses that fail validation. Google Public DNS (8.8.8.8) supports DNSSEC validation but does not enforce it as strictly. OpenDNS and Norton ConnectSafe support DNSSEC but with varying levels of strictness. AdGuard DNS validates DNSSEC responses. If DNSSEC is a priority, Quad9 and Cloudflare are the strongest choices because they reject unsigned or invalid responses automatically.

Malware and Phishing Blocking

DNS-level blocking of malware and phishing works by maintaining databases of known-malicious domains and refusing to resolve them. The effectiveness of this approach depends on the breadth and accuracy of the underlying threat intelligence.

How DNS Filtering Stops Malware

Most malware needs to communicate with external servers to function. Trojans contact command-and-control servers for instructions. Ransomware operators host decryption key exchanges on their own infrastructure. Spyware exfiltrates stolen data to remote endpoints. All of these operations require DNS resolution. By blocking the domains associated with these servers, DNS filtering disrupts the malware lifecycle at a critical point.

The advantage over traditional antivirus is speed. A new malware sample might take hours to be added to antivirus signature databases, but the domain it communicates with can be blocked within minutes of being identified. Threat intelligence feeds update continuously, and the best security DNS providers refresh their blocklists multiple times per day. This means the window between a threat being discovered and being blocked at the DNS level is measured in minutes, not hours.

DNS filtering also handles the scale problem. An enterprise with thousands of endpoints cannot run real-time antivirus scans on every device simultaneously, but a DNS resolver can block a malicious domain for every device on the network with a single entry in its blocklist. This makes DNS-level protection one of the most efficient security measures available.

How DNS Filtering Stops Phishing

Phishing attacks rely on lookalike domains — registering bank-login.com to impersonate bankofamerica.com, or creating a convincing Microsoft 365 login page on a subtly different URL. DNS-level phishing protection identifies these domains through several techniques:

Brand impersonation detection algorithms analyze domain names for patterns that mimic known brands — combinations of brand names with generic terms like "login," "secure," "verify," or "account." Newly registered domains are flagged at higher risk, since the majority of phishing domains are active for less than 72 hours before being taken down.

Certificate transparency logs are monitored for certificates issued to suspicious domains. If someone obtains an SSL certificate for a domain that closely resembles a major brand, the security provider can flag it before the phishing site goes live.

Community reporting plays a significant role. Users who encounter phishing pages can report the URLs, which are then analyzed and added to blocklists. The best providers combine automated detection with human verification to minimize false positives while catching threats quickly.

Limitations of DNS Blocking

DNS blocking is not a complete security solution. It cannot protect against malware delivered through USB drives, email attachments, or zero-day exploits that use previously unknown domains. It cannot stop phishing attacks that use legitimate infrastructure — a phishing page hosted on a compromised WordPress site on a reputable hosting provider will not be blocked at the DNS level. And it cannot prevent social engineering attacks where the user is manipulated into voluntarily providing credentials.

For these reasons, DNS-level security works best as one layer in a defense-in-depth strategy. Pair it with a reputable antivirus, enable multi-factor authentication on important accounts, and maintain awareness of phishing tactics. DNS blocking eliminates a significant percentage of threats, but it is not a silver bullet.

DNS Security for Business

Businesses face a different threat landscape than home users. Employees click links in emails, access personal accounts on work devices, connect to public Wi-Fi while traveling, and inadvertently expose corporate credentials through phishing. DNS-level security addresses many of these risks at the network layer, protecting every device without requiring per-endpoint software installation.

Enterprise DNS Security Solutions

Cisco Umbrella (the enterprise version of OpenDNS) is the most widely deployed DNS security platform for businesses. It provides real-time threat intelligence, granular policy management, and detailed analytics across all DNS traffic. Umbrella can enforce security policies based on user, device, location, and time of day — blocking personal cloud storage during work hours, restricting access to high-risk categories, and detecting DNS tunneling used for data exfiltration.

Palo Alto Networks DNS Security (formerly Zscaler Internet Access DNS) integrates DNS filtering with a broader security stack that includes sandboxing, CASB, and DLP. For organizations already using Palo Alto firewalls, the DNS security module provides centralized policy enforcement and correlated threat visibility.

Cloudflare Gateway extends Cloudflare's consumer DNS security to the enterprise with identity-aware policies, device posture checks, and integration with identity providers like Okta and Azure AD. It blocks threats at the DNS layer while also providing Secure Web Gateway, CASB, and data loss prevention capabilities.

Benefits of DNS Security for Business

The primary benefit is coverage. Every device on the corporate network — including IoT devices, guest devices, and contractor laptops — is protected by DNS-level filtering without requiring software installation. This eliminates the gap between what your endpoint protection covers and what it does not.

DNS security also provides visibility. By monitoring DNS traffic, security teams can identify compromised devices (which often communicate with known C2 domains), detect data exfiltration via DNS tunneling, and spot unusual patterns that indicate a breach in progress. DNS logs, when collected and analyzed properly, are one of the most valuable sources of security telemetry.

For remote and hybrid workforces, DNS security follows the user. When employees connect to public Wi-Fi at coffee shops, airports, or hotels, a DNS security agent or configured resolver ensures they are still protected by the same threat intelligence and policies as office devices. This is particularly important for preventing credential theft on untrusted networks.

Implementation Considerations

Deploying DNS security across an organization requires planning. Start with a monitoring mode — point DNS at the security resolver but do not block anything. Analyze the DNS traffic for a week to identify legitimate services that might be flagged, false positives that need exceptions, and shadow IT that the security team did not know about. Then transition to blocking mode with policies tailored to the organization's risk profile.

For organizations with strict compliance requirements (healthcare, finance, government), ensure the DNS security provider meets relevant regulatory standards. SOC 2 Type II certification, GDPR compliance, and data processing agreements are baseline requirements. Review the provider's data retention policy carefully — some enterprise DNS providers retain query logs for analytics, which may conflict with privacy requirements.

Frequently Asked Questions

Test Your DNS Speed

Security and speed are not mutually exclusive. Run our DNS speed test to see which security-focused resolver performs best from your location. The test benchmarks 17+ resolvers simultaneously using real DNS-over-HTTPS queries, measures actual response times, and delivers results in seconds. No downloads. No registration. No data collected.

Run DNS Speed Test

After switching to a security DNS, run the test again to confirm the new resolver is performing well from your network. Then check out our DNS over HTTPS guide to encrypt your queries, or read the best DNS for privacy to compare providers on privacy and logging policies.