How Zero Ads blocks ads on iPhone
Most ads in apps and on websites are fetched from separate advertising and tracking servers. Before your iPhone can load anything from those servers, it looks up their address with a DNS query. Zero Ads changes where those lookups go.
When you switch protection on, Zero Ads installs an encrypted DNS configuration using Apple’s DNS settings framework. Your iPhone then sends DNS queries over HTTPS (DoH) to the filtering provider you pick in the app. If a domain is on that provider’s ad or tracker list, the lookup is refused and the ad request never connects.
Because this works at the system DNS level, it applies across supported apps, games and browsers — not only Safari. It is a DNS configuration, not a traffic tunnel: Zero Ads does not route your browsing through its own servers and does not change your location.
How to block ads in iPhone apps with Zero Ads
- Install Zero Ads from the App Store (iOS 17 or later).
- Choose Ads & Trackers — the free mode that blocks ads.
- Allow the DNS configuration when iOS asks. If it shows as installed but inactive, the app’s activation guide shows exactly which DNS entry to select in Settings › General › VPN & Device Management.
- Check the status on the Filter screen, which shows your provider, its endpoint and whether DNS filtering is active.
- Optional: turn on the Safari blocker in Safari’s extension settings for extra filtering on websites.
Already using another VPN app or DNS profile? Only one DNS configuration can be in charge at a time, so check which one is active if ads come back.
Filtering choices on iPhone
On iPhone, each mode selects a different filtering DNS provider. Only Ads & Trackers blocks ordinary ads; the Pro choices focus on threats or adult content.
| Mode | Provider | What it filters | Plan |
|---|---|---|---|
| Ads & Trackers | AdGuard DNS Default | Known ad and tracker domains | Free |
| Cloudflare Filtered | Cloudflare 1.1.1.2 | Malware domains; ordinary ads pass through | Pro |
| Quad9 Filtered | Quad9 9.9.9.9 | Threat domains; ordinary ads pass through | Pro |
| Family | Cloudflare 1.1.1.3 | Threat and adult-content domains; no ad blocking | Pro |
Prices are shown in the app. Filtering happens at the provider you choose, so that provider’s privacy policy applies; the Filter screen links to it.
Safari ad blocker vs DNS ad blocking
A Safari content blocker gives Safari a list of rules, and Safari itself hides or blocks matching page elements. It is precise on websites but only works inside Safari.
DNS filtering works everywhere your iPhone looks up a domain — apps, games and other browsers — but it can only block whole domains. Zero Ads includes both: encrypted DNS for the whole phone and a Safari content blocker you enable separately. Using both gives the widest coverage.
What an iPhone ad blocker can’t block
No DNS filter removes every ad, and Zero Ads doesn’t claim to. Expect fewer ads, not zero, in these cases:
- Same-domain ads. When an app serves ads from the same domain as its content (common with video and social apps, including YouTube), blocking the domain would break the app, so those ads usually stay.
- Apps with their own DNS. An app that resolves domains itself can bypass the system setting.
- Built-in promotions. Rewarded videos and in-game offers that are part of the app aren’t separate ad requests.
Results vary by app, website and network. Our guide to stopping ads in iPhone games goes through these cases in detail.
Privacy on iPhone
With DNS filtering on, your lookups go to the provider you selected over an encrypted connection, and that provider’s policy applies. Zero Ads on iPhone does not keep blocked-query statistics. Purchases are handled by the App Store, which lists the data used for app functionality on the app’s store page. Read the Zero Ads privacy policy for details.
DNS filtering complements, but doesn’t replace, Apple’s own controls: App Tracking Transparency limits cross-app tracking, and App Privacy Report shows which domains apps contact.
