Browser extensions block ads in one browser on one device — a DNS-based ad blocker blocks known ad and tracker domains for every device on your home network at once, including phones, smart TVs, and game consoles that can't run a browser extension at all. It works at a different layer than a browser plugin, which is exactly why it covers ground browser extensions can't reach.
How DNS Ad Blocking Actually Works
Every time a device on your network tries to load a webpage or an ad, it first looks up the address of that domain through DNS (the system that translates domain names into the numeric addresses computers actually use). A DNS-based ad blocker sits between your devices and the internet, checking every lookup against a list of known ad and tracker domains — if the domain is on the blocklist, it refuses to resolve it, so the ad or tracker never loads at all, rather than being hidden after loading the way some browser extensions work.
Pi-hole: The Most Common Option
Pi-hole is free, open-source software originally built to run on a Raspberry Pi (hence the name), though it also runs fine on a spare old PC, a NAS, or inside a virtual machine — it doesn't need much processing power. Basic setup:
- Install Pi-hole on the always-on device you've chosen (a Raspberry Pi is the most common, cheapest option, but any always-on Linux-capable machine works).
- Once installed, Pi-hole runs its own DNS server with a web dashboard for managing blocklists and viewing what's being blocked in real time.
- In your router settings, change the DNS server your network hands out to devices to point at the Pi-hole's local IP address, instead of your ISP's default DNS or a public one.
- Devices on the network automatically start using Pi-hole for DNS lookups the next time they reconnect, no per-device setup required.
Alternatives If You Don't Want to Run Your Own Server
Several cloud-based DNS services offer similar ad and tracker blocking without needing a device running at home — you just point your router's DNS settings at their servers instead. These trade a bit of the customization and local dashboard of a self-hosted Pi-hole for zero setup and no dependency on a device staying powered on at home, which matters if you don't want another always-on box to maintain.
What It Blocks Well, and What It Doesn't
- Blocks well: ads and trackers served from separate ad-network domains, which is the majority of display advertising and a large share of tracking scripts across ordinary websites and apps.
- Doesn't block: ads served from the same domain as the content itself (first-party ads), which many major platforms and streaming services deliberately use specifically to get around this kind of blocking. YouTube's in-video ads, for instance, are largely served this way and mostly slip past DNS-level blocking.
- Doesn't replace HTTPS/encryption protections or a VPN — DNS blocking stops specific known-bad domains from resolving, it doesn't encrypt your traffic or hide your browsing from your ISP the way a VPN does; the two solve different problems.
Maintenance and Realistic Expectations
Blocklists need periodic updates as ad networks change domains, and most DNS ad blocker software handles this automatically on a schedule rather than requiring manual updates. Expect occasional breakage — a site failing to load a feature, a checkout page not working — since blocklists sometimes catch legitimate third-party services alongside ads; most tools make it simple to temporarily disable blocking or whitelist a specific domain when this happens, rather than needing to abandon the whole setup.
Router-Level vs Per-Device DNS
Setting DNS at the router level, as described above, is what makes every device benefit automatically without individual configuration — this differs from setting a private, encrypted DNS on a single phone, which only affects that one device. If you've already set up private DNS on individual phones, know that a per-device DNS setting generally overrides the router-wide one on that specific device, so the two approaches don't automatically combine without checking each device's settings.
A DNS ad blocker is one of the few home network changes that keeps working quietly in the background for every device, without asking anyone in the house to install anything or change a habit — set up once at the router level, it just filters continuously from that point on.