Quad9

Quad9 is a free DNS resolver for people who want an added layer of protection against malicious domains. It suits households and organizations that value encrypted DNS and privacy without needing to manage browsing rules. Its focused protection costs nothing, but it cannot replace content controls or custom domain policies.

Overview

Quad9 is a recursive, anycast DNS platform that blocks requests to domains associated with malware, viruses, adware, phishing, and scams. It draws on more than 20 threat-intelligence partners, making it a security-focused resolver rather than a general-purpose web-filtering system.

Quad9 says it does not store end-user IP addresses and is governed by Swiss privacy law. It reports 99.999% uptime for its global anycast service. ISPs, service providers, and other organizations planning to send large-scale DNS traffic are asked to contact Quad9 first.

Key features

Threat blocking and privacy

Blocking known malicious domains can reduce exposure to common online threats without a subscription or sign-up. Quad9 also shares anonymized volumetric information and rough threat geography with its intelligence partners. That supports threat intelligence, but users should understand that some aggregate threat data is shared even though end-user IP addresses are not stored.

Encrypted DNS and DNSSEC

DNS over TLS, DNS over HTTPS, and DNSCrypt provide several encrypted ways to send DNS queries. Quad9 also validates DNSSEC on its resolver services. Together, these features make it a good fit for users who want security at the DNS layer; they do not give administrators control over access to otherwise legitimate sites.

Integrations and support

Setup guides cover Cloudflared, Pi-hole, and open-source routers including pfSense, OPNsense, OpenWrt, MikroTik RouterOS, and IPFire. Quad9’s support team assists with setup questions and issues, while the integrations make the resolver usable in a range of home and network configurations.

Pricing

Quad9 DNS service: free. It is free for everyone, with no contract and no sign-up process. There is no paid plan to unlock custom domain rules or category controls: those capabilities are outside the service’s scope. The free service includes roaming protection and activity reports.

Platforms

Quad9 supports Android, iOS, Linux, macOS, and Windows. Its documentation for DNS tools and routers also helps users integrate it into supported network setups.

Who it's for

Quad9 is a strong choice for home users and organizations seeking a no-cost resolver that blocks known malicious domains and supports encrypted DNS and DNSSEC. Its broad intended audience extends from individuals to enterprises, but large-scale DNS operators should contact Quad9 before sending substantial traffic.

It is not the right fit for parents or administrators who need category-based filtering, custom allowlists or blocklists, or policies tailored to particular users or networks. Quad9 focuses on threats, not general browsing restrictions.

Pros and cons

• Pros: Free for everyone, with no contract or sign-up, so there is little friction to adopting its threat-focused DNS protection.
• Pros: DNS over TLS, DNS over HTTPS, DNSCrypt, and DNSSEC validation give users multiple encrypted DNS options and resolver-side validation.
• Pros: Quad9 says it does not store end-user IP addresses and operates under Swiss privacy law.
• Cons: No content filtering or custom domain policies, limiting its usefulness for parental controls and organization-specific access rules.
• Cons: Large-scale DNS users are asked to contact Quad9 before sending traffic, so the simple self-service fit is less direct for major operators.

Alternatives

For a broader directory of options, see DNS Filtering Software.

• AdGuard DNS is worth considering if open-source code matters; AdGuard says its DNS service is open source and offers a free plan.
• Comodo Secure DNS may suit enterprises and MSPs looking for a free plan capped at 300,000 DNS requests per month.
• NextDNS offers a free plan with 300,000 queries per month, unlimited devices and configurations, and all features; consider it if those controls matter more than Quad9’s narrower approach.
• NxFilter is an alternative with a free plan for commercial and non-commercial use.
• OpenDNS FamilyShield is the more relevant option when preconfigured adult-content blocking is the priority.
• Technitium DNS Server is a free, open-source self-hosted DNS server for users who want to run their own service.
• Blocky is a free, open-source self-hosted DNS proxy.
• Pi-hole is a free, open-source option that runs on supported Linux hardware or in Docker.

Verdict

Choose Quad9 if you want a free resolver that combines malicious-domain blocking with encrypted DNS and DNSSEC validation, without requiring an account. Its privacy stance and threat-focused scope are persuasive for everyday DNS protection. Look elsewhere if you need category filtering or custom domain policies; Quad9 is not designed to provide them.