A public recursive name server (also called public DNS resolver) is a

name server A name server is a computer application that implements a network service for providing responses to queries against a directory service. It translates an often humanly meaningful, text-based identifier to a system-internal, often numeric identi ...

service that networked computers may use to query the

Domain Name System The Domain Name System (DNS) is a hierarchical and distributed name service that provides a naming system for computers, services, and other resources on the Internet or other Internet Protocol (IP) networks. It associates various information ...

(DNS), the decentralized Internet naming system, in place of (or in addition to) name servers operated by the local

Internet service provider An Internet service provider (ISP) is an organization that provides a myriad of services related to accessing, using, managing, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, no ...

(ISP) to which the devices are connected. Reasons for using these services include: * speed, compared to using ISP DNS services * filtering (security,

ad-blocking Ad blocking (or ad filtering) is a software capability for blocking or altering online advertising in a web browser, an application or a network. This may be done using browser extensions or other methods or browsers with inside blocking. Hist ...

, porn-blocking, etc.) * reporting * avoiding

censorship Censorship is the suppression of speech, public communication, or other information. This may be done on the basis that such material is considered objectionable, harmful, sensitive, or "inconvenient". Censorship can be conducted by governmen ...

* redundancy (smart caching) * access to unofficial alternative top level domains not found in the official

DNS root zone The DNS root zone is the top-level DNS zone in the hierarchical namespace of the Domain Name System (DNS) of the Internet. Before October 1, 2016, the root zone had been overseen by the Internet Corporation for Assigned Names and Numbers (ICANN ...

*temporary unavailability of the ISP's name server Public DNS resolver operators often cite increased privacy as an advantage of their services; critics of public DNS services have cited the possibility of mass data collection targeted at the public resolvers as a potential risk of using these services. Most services now support secure DNS lookup transport services such as DNS over TLS (DoT), DNS over HTTPS (DoH) and DNS over QUIC (DoQ). Public DNS resolvers are operated either by commercial companies, offering their service for free use to the public, or by private enthusiasts to help spread new technologies and support non-profit communities.

Notable public DNS service operators

References

{{Reflist, 30em

External links

Home page of the DNSCrypt project: Public DNS servers
Domain Name System Alternative Internet DNS services Distributed data structures