Definition
Smart DNS is a service that rewrites specific DNS responses to redirect the user through proxy servers in other countries — but only for the small number of domains where geo-spoofing is needed (Netflix, Hulu, BBC iPlayer, etc.). All other traffic resolves normally and goes directly to the destination, without any proxy involvement. The result is a service that allows access to geo-restricted content without paying the speed cost of a full VPN.
Smart DNS vs VPN
The trade-offs are clear. Smart DNS is faster because it does not encrypt or proxy non-targeted traffic, and it works on devices that cannot run VPN clients (smart TVs, game consoles, certain streaming sticks). It does not, however, hide your IP from anyone except the geo-blocked services it is configured for, and it provides no encryption — your ISP still sees everything you do. For privacy, Smart DNS is essentially useless; for unlocking geographic content on a smart TV with minimal speed cost, it is sometimes the better tool.
Bundled With VPNs
Many VPN providers offer Smart DNS as a bundled feature for subscribers, alongside their full VPN service. Users can pick the appropriate tool per use case — Smart DNS for streaming on devices that cannot run VPN clients, full VPN for privacy-sensitive activity. As streaming services have become more sophisticated at detecting geo-spoofing, Smart DNS has become less reliable than it was in the mid-2010s.