DNS turns names like techsupportoffice.com into the numeric addresses your device connects to. Your internet provider normally supplies DNS automatically, but changing it can improve reliability, privacy, or access to sites that fail through the default resolver.
Does this affect you?
Use this if you want DNS changed for the whole home from the router, or only for one Windows PC, Mac, iPhone, or Android device.
Change DNS on your router
Router-level DNS is the cleanest option because every device can inherit it automatically.
- Log into the router admin page from a connected device, usually at 192.168.0.1 or 192.168.1.1.
- Find Internet Settings, WAN Setup, Advanced DNS, or a similar DNS menu.
- Change DNS from Automatic or Obtain from ISP to Manual.
- Enter a primary and secondary resolver. Cloudflare uses 1.1.1.1 and 1.0.0.1. Google uses 8.8.8.8 and 8.8.4.4.
- Save and restart the router if prompted.
- Reconnect devices or renew their network connection if they keep using the old DNS briefly.
Change DNS on one device
Use per-device DNS when you only want the change on one computer or phone.
- Windows: open Settings > Network & Internet, choose Wi-Fi or Ethernet, open your connection, select Edit beside DNS server assignment, switch to Manual, enable IPv4, and enter preferred and alternate DNS.
- Mac: open System Settings > Wi-Fi, click Details beside the network, open DNS, and add addresses with the plus button.
- iPhone: open Settings > Wi-Fi, tap the info button beside the network, tap Configure DNS, choose Manual, and add the address.
- Android: open Settings > Network & Internet > Private DNS, choose Private DNS provider hostname, and enter a hostname such as 1dot1dot1dot1.cloudflare-dns.com or dns.google. Android Private DNS does not use numeric IP addresses in that box.
More control
Flush stale DNS after changing it
Old lookups can remain cached. On Windows, run ipconfig /flushdns in Command Prompt. On Mac, use sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder in Terminal.
Choose a provider for the job
Cloudflare 1.1.1.1 emphasizes speed and privacy. Google Public DNS is fast and highly available. OpenDNS, at 208.67.222.222, can add optional filtering features for families.
Some services prefer ISP DNS
A streaming site or regional service can occasionally route better through your provider DNS. If only one service slows down after the switch, try another resolver or return to automatic DNS.
Sources
- Cloudflare – 1.1.1.1 Public DNS Resolver Documentation (2025)
- Google Public DNS – Configuration Guide (2025)
- Microsoft Support – Change TCP/IP Settings in Windows (2025)