Quad9

Quad9 is a no-cost DNS resolver focused on blocking domains tied to online threats. It suits people who want that protection without an account or subscription; its narrow remit makes it a poor choice for managing everyday browsing access.

Overview

Quad9 routes DNS requests through a global anycast network and uses data from more than 20 threat-intelligence partners to identify domains associated with malware, viruses, adware, phishing, and scams. That makes it a focused security layer, not a general web-control service. Its reported 99.999% uptime is reassuring for a service that sits between devices and websites, although large organizations and service providers are asked to contact Quad9 before sending substantial DNS traffic.

Quad9 says it does not store end-user IP addresses and operates under Swiss privacy law. It also shares anonymized volume information and rough threat geography with its intelligence partners, a trade-off worth knowing for users weighing privacy alongside threat detection.

Key features

Threat blocking, not broad filtering

Blocking known malicious destinations can help reduce exposure to phishing and other threats without requiring users to maintain their own blocklists. But Quad9 does not filter by content category or let users create custom domain policies. Choose another tool if you need parental controls, organization-specific site rules, or the ability to allow or block particular domains.

Encrypted and validated DNS

DNS over TLS, DNS over HTTPS, and DNSCrypt give users several options for encrypting DNS queries. Quad9 also validates DNSSEC on its resolver services. Together, these features make it a sensible fit for people who want encrypted DNS and validation without a paid plan, though they do not expand its limited policy controls.

Network integrations and support

Documentation includes setup guides for Cloudflared, Pi-hole, and open-source routers such as pfSense, OPNsense, OpenWrt, MikroTik RouterOS, and IPFire. That breadth is useful to network administrators who want to use Quad9 within an existing setup. Its support team can help with setup questions and issues, while large-scale operators should make contact before sending high volumes of traffic.

Pricing

Quad9 DNS service: free. The service is free for everyone, with no contract and no sign-up process. That removes subscription and account friction, but there is no paid tier that adds category filtering or custom domain policies; those controls are not part of Quad9's offering.

Platforms

Quad9 supports Android, iOS, Linux, macOS, and Windows. Router and software integration guides also give users ways to incorporate it into supported network setups, rather than limiting its use to a single desktop or mobile platform.

Who it's for

Quad9 is best for home users and organizations that want a free resolver to block known malicious domains, with encrypted DNS options and a privacy approach that avoids storing end-user IP addresses. It is less suitable for parents or administrators who need to control access to non-malicious sites, define custom domain rules, or apply content categories. Larger service providers should contact Quad9 before routing large-scale DNS traffic through the service.

Pros and cons

• Pro: Free for everyone with no sign-up or contract, so there is little friction to adopting its malicious-domain protection.
• Pro: Three encryption options and DNSSEC validation serve users who want more than an unencrypted resolver.
• Pro: Quad9 says it does not retain end-user IP addresses and is governed by Swiss privacy law.
• Con: No content filtering or custom domain policies, so it cannot enforce household or organization-specific browsing rules.
• Con: Sharing anonymized volume data and rough threat geography with intelligence partners may not suit users who prefer threat-data sharing to be absent.
• Con: Large-scale DNS users are asked to contact Quad9 first, adding a step for providers and enterprises considering high-volume use.

Alternatives

DNS Filtering Software is the broader category to explore if Quad9's limited policy controls do not meet your needs.

• AdGuard DNS is a free-plan option to consider if open-source code and support across platforms including API and self-hosted setups matter to you.
• Comodo Secure DNS may suit enterprises or MSPs that want a free plan with up to 300,000 DNS requests per month.
• NextDNS is worth considering if you want unlimited devices and configurations within a free plan capped at 300,000 queries per month.
• NxFilter offers a free software option for commercial or non-commercial use, with a separate paid Jahaslist Monthly plan.
• OpenDNS FamilyShield is the more direct alternative when preconfigured adult-content blocking is the priority; it is free and requires no sign-up.
• Technitium DNS Server is a free, open-source, self-hosted DNS server for those who prefer to run their own service.
• AdGuard is another freemium option, with annual personal and family plans as well as a lifetime plan.
• CleanBrowsing offers a paid Basic plan at $8.99 a month, with up to 25 devices or 3.75 million requests per month.

Verdict

Choose Quad9 if you want a free, account-free DNS resolver whose main job is blocking known malicious domains, and you value encrypted DNS, DNSSEC validation, and a policy against storing end-user IP addresses. Look elsewhere if your main need is content filtering or custom domain rules: Quad9's security focus is useful precisely because it is narrow, but that same limit rules it out as a general browsing-control tool.