How to Clear the DNS Cache on an iPhone

Why Your iPhone Needs a DNS Flush

The Domain Name System (DNS) acts as the phonebook of the internet. When you type www.digitash.com into Safari, the DNS translates that human-readable name into a numerical IP address so your iPhone can connect to the server. To speed up your browsing, your iPhone saves these recent translations in a temporary local storage area known as the DNS cache.

Usually, this background process is flawless. However, if a website recently migrated to a new server or updated its security protocols, its IP address will change. If your iPhone is still holding onto the old IP address in its DNS cache, the website will simply refuse to load. You might see a blank white screen, a “Server Not Found” error, or a broken layout, even though the website loads perfectly on your laptop.

To fix this, you must flush the DNS cache, forcing the iPhone to request the brand-new IP address from the server. Because Apple prefers to keep iOS simple, there is no single “Clear DNS” button in the Settings app. Instead, you have to use one of the two methods below.

Method 1: The Aeroplane Mode Toggle (The Fastest Way)

The DNS cache in iOS is intrinsically linked to the active network state. The fastest and most reliable way to dump the cache is to completely sever the iPhone’s connection to the outside world, forcing the networking stack to reset itself when the connection is re-established.

1. Unlock your iPhone and swipe down from the top-right corner of the screen to open the Control Centre. (If you have an older iPhone with a physical Home button, swipe up from the bottom edge of the screen).
2. Tap the Aeroplane mode icon (the airplane symbol). It will turn orange, and your Wi-Fi and cellular icons will disappear.
3. Wait for exactly 15 seconds. This delay is critical; if you toggle it back off too quickly, iOS will not actually dump the cache.
4. Tap the Aeroplane mode icon again to turn it off.
5. Wait a few moments for your phone to reconnect to your Wi-Fi router or cellular tower.

Open Safari and attempt to load the problematic webpage again. In almost all cases, the DNS cache is now clear, and the site will load normally.

Method 2: Rebooting the iPhone (The Hard Reset)

If the Aeroplane mode trick did not work, the DNS cache might be corrupted at a deeper system level, or the specific app you are using (like a third-party social media app) might be holding onto its own independent network cache.

A full system reboot clears all volatile memory (RAM) on the device, including every network cache.

1. For modern iPhones (Face ID): Press and hold the Side button (on the right) and the Volume Down button (on the left) simultaneously until the power-off slider appears on the screen.
2. For older iPhones (Home button): Press and hold the Side button or Top button until the power-off slider appears.
3. Drag the “slide to power off” toggle all the way to the right.
4. Wait at least 30 seconds for the screen to go completely black and the internal hardware to power down.
5. Press and hold the Side button again until you see the white Apple logo appear.

Once the phone reboots, enter your passcode and try accessing the website again.

What If the Website Still Won’t Load?

If you have flushed the DNS cache using both Aeroplane mode and a hard reboot, and the website still refuses to load on your iPhone, the problem is no longer your local cache.

The issue is likely with your Internet Service Provider’s (ISP) DNS servers, which can sometimes be incredibly slow to update their global records.

If you urgently need access to the site, you can bypass your ISP’s slow servers entirely by switching your iPhone to use Google’s Public DNS or Cloudflare’s DNS.

1. Go to Settings > Wi-Fi.
2. Tap the blue “i” (information) icon next to your connected Wi-Fi network.
3. Scroll down and tap Configure DNS.
4. Change it from Automatic to Manual.
5. Delete the existing server addresses and add 8.8.8.8 (Google) or 1.1.1.1 (Cloudflare).
6. Tap Save.

This will force your iPhone to use a much faster, globally updated DNS registry, which almost always resolves stubborn loading issues.