Broken link between phone and internet globe diagram
DNS problems on iOS often look like “server not found,” endless loading, or apps that act offline even though Wi‑Fi shows connected.

Start with the fastest fix first.

This guide is a symptom → cause → fix map, so you can jump to what matches what you’re seeing.

Quick prep: note whether this happens on Wi‑Fi, cellular, or both. That single detail narrows the cause a lot.

1. Symptom: Nothing loads anywhere (Wi‑Fi and cellular), but signal looks fine

Likely cause: a stuck network state, a bad DNS cache path, or an iOS network service glitch.

Fast fix: toggle connectivity in the order below (stop when it’s resolved).

  • Turn Airplane Mode on for 10 seconds, then off.
  • Toggle Wi‑Fi off/on, then toggle Cellular Data off/on.
  • Restart the iPhone/iPad (a full reboot, not just screen off/on).

If it immediately works after Airplane Mode, you’re likely dealing with a transient resolver/route issue, not a “real” DNS misconfiguration.

2. Symptom: Works on cellular, fails on Wi‑Fi (or only fails on one Wi‑Fi network)

Likely cause: DNS settings or filtering on that Wi‑Fi network (router DNS, captive portal, Pi-hole/ad-block DNS, or ISP DNS trouble).

Fix mapping: pick the line that matches your setup.

  • If it fails only at home: restart the router/modem (unplug 30–60 seconds). Then test again.
  • If it fails on public Wi‑Fi: open Safari and try loading a plain HTTP site (some networks force a sign-in page). If a sign-in page appears, complete it, then retry your app/site.
  • If you use custom DNS at home (ad-block DNS/Pi-hole): temporarily switch iOS to automatic DNS for that Wi‑Fi (steps in section 4) to confirm whether DNS filtering is the blocker.

Wi-Fi router to DNS path with failing branch
If other devices on the same Wi‑Fi also fail, focus on the router/ISP side first.

3. Symptom: Works on Wi‑Fi, fails on cellular (or only on one carrier)

Likely cause: carrier DNS/route issues, Private Relay/VPN interaction, or a local APN/carrier settings mismatch.

Fast fix:

  • Toggle Cellular Data off/on.
  • Check for Carrier Settings update: Settings > General > About (wait ~30 seconds on that screen).
  • If you use a VPN, disconnect it temporarily and retest.

If it’s only one app: it may be blocking cellular data. Check Settings > Cellular, find the app, and ensure it’s allowed.

4. Symptom: Some sites/apps work, others fail (timeouts, “can’t find server”, or partial loading)

Likely cause: a DNS resolver mismatch (custom DNS, encrypted DNS profile, VPN DNS), IPv6-only quirks on a network, or content filtering breaking specific domains.

Fix: check DNS at the Wi‑Fi level first.

  • Settings > Wi‑Fi > tap the i next to the network
  • Tap Configure DNS
  • Set to Automatic (fastest “known good” test)
  • Reconnect to Wi‑Fi and retry the failing site/app

What the result means:

  • If Automatic fixes it, your previous DNS server (or ad-block DNS) is the cause. You can switch back later and adjust allowlists/filters, or pick a more reliable DNS provider.
  • If Automatic does not fix it, the issue is more likely routing/filtering/VPN/relay than DNS itself.

iOS DNS settings switching from custom to automatic
If you’re using a managed DNS profile (MDM/school/work), those settings can override what you choose here.

5. Symptom: Safari fails but other apps work (or the reverse)

Likely cause: app-specific DNS-over-HTTPS/Private Relay behavior, content blockers, or a VPN split-tunnel rule.

Fix mapping:

  • If Safari is the one failing: temporarily disable content blockers (Settings > Safari > Extensions) and retry. Some blockers break DNS-dependent redirects or captive portals.
  • If multiple browsers fail but some apps work: look for a VPN or DNS profile that applies only to certain traffic.
  • If one app fails on every network: it may be the app’s own outage or its domain being filtered. Try the same service on another device/network to confirm.

Keep this simple: change one thing, test, then either keep it or revert it.

6. Symptom: Problems started right after installing a VPN, “security” app, or DNS profile

Likely cause: the VPN/profile is providing DNS (or filtering) and either the DNS server is down or the filter blocks domains the app/site needs.

Fix:

  • Settings > VPN: disconnect and test.
  • Settings > General > VPN & Device Management: look for installed DNS/security profiles and temporarily remove/disable (if you control it).

Stop point: if the device is managed by work/school, don’t remove management profiles—ask the admin whether DNS filtering or an outage is affecting you.

7. Symptom: You’ve tried everything above and it still fails (especially across multiple networks)

Likely cause: corrupted network settings, a persistent VPN/dns profile conflict, or a deeper iOS networking issue.

Advanced fix (big reset, but safe): Reset Network Settings.

  • Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings

What it changes: Wi‑Fi networks and passwords are cleared, VPN/APN-related network settings revert, and you’ll need to rejoin Wi‑Fi.

If DNS failures continue even after this reset, test the same sites on another device on the same network. If only this iPhone/iPad fails everywhere, it’s time to check for iOS updates or contact Apple Support with the exact error message and networks tested.

Final thoughts

If you want the quickest win, set Wi‑Fi DNS back to Automatic and restart the connection. It’s the fastest way to separate “DNS setting problem” from “network/ISP problem.”

Once it’s stable, you can reintroduce custom DNS, VPNs, and blockers one at a time to find the specific trigger.