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

name server A name server refers to the server component of the Domain Name System (DNS), one of the two principal namespaces of the Internet. The most important function of DNS servers is the translation (resolution) of human-memorable domain names (example. ...

service that networked computers may use to query the

Domain Name System The Domain Name System (DNS) is a hierarchical and distributed naming system for computers, services, and other resources in the Internet or other Internet Protocol (IP) networks. It associates various information with domain names assigned to ...

(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 services for accessing, using, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, non-profit, or otherwise private ...

(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. Technologies and native countermeasure ...

, 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 governments ...

* redundancy (smart caching) * access to unofficial

alternative top level domain The Internet uses the Domain Name System (DNS) to associate numeric computer IP addresses with human-readable names. The top level of the domain name hierarchy, the DNS root, contains the top-level domains that appear as the suffixes of all Intern ...

s 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. Several services now support secure DNS lookup transport services such as

DNS over HTTPS DNS over HTTPS (DoH) is a protocol for performing remote Domain Name System (DNS) resolution via the HTTPS protocol. A goal of the method is to increase user privacy and security by preventing eavesdropping and manipulation of DNS data by man-i ...

(DoH) and

DNS over TLS DNS over TLS (DoT) is a network security protocol for encrypting and wrapping Domain Name System (DNS) queries and answers via the Transport Layer Security (TLS) protocol. The goal of the method is to increase user privacy and security by prevent ...

(DoT). 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