What Does Flushing DNS Cache Do? Flushing the Cache Explained

Ever wonder what happens when you flush your DNS cache? When the OS discards every stored domain‑to‑IP mapping, it forces a fresh lookup from the authoritative servers. This guide walks you through clearing the cache on Windows 11, macOS, Linux, and mobile devices. On Windows 11, run ipconfig /flushdns. If you’re dealing with DNS‑related hiccups, flushing is often the first thing to try—it's a standard troubleshooting step.

The Tangible Benefits

Think of your browser as a library. If the index card for a book is outdated, you’ll keep looking in the wrong aisle. Flushing the cache is like updating that card—so you find the right book instantly.

A Real‑World Example

In 2025, a small marketing agency hit intermittent “site not found” errors after a server migration. Their IT team ran the flush command on all Windows 11 machines, and the error vanished within minutes. The team saved hours of debugging and avoided costly downtime.

Why Privacy Matters

When your device remembers every domain you visited, it also holds clues that a curious neighbor or a rogue Wi‑Fi hotspot could exploit. Clearing the cache removes those clues, making it harder for attackers to map your browsing habits.

Speed and Reliability

Because the cache is refreshed, each new request goes straight to the authoritative server. The result? Faster load times and fewer hiccups. It’s like clearing the cobwebs from a doorway so the air flows freely.

Quick‑Reference Table of Commands

Common Errors and When a DNS Flush Is Unnecessary

• Error: “Could not resolve host” after flush – usually indicates a network outage, not a cache issue.
• Error: No change in browsing behavior – the site may be down or DNS changes may not yet have propagated.
• When unnecessary: If you’re not experiencing any connectivity issues or stale content, a flush is optional and can be skipped.

The Bottom Line

Flushing DNS is a quick, low‑risk step that keeps your connections fresh, protects your privacy, and shields you from a common attack vector. And don’t worry—our next section will walk you through the exact commands for every device you own.

In 2026, 27 % of enterprises fell victim to cache poisoning, so flushing regularly cuts that risk dramatically.

We hear a lot about DNS cache, but what does “flushing” it actually do? Think of your browser’s memory as a sticky note that keeps old addresses. Flushing wipes that note, forcing the browser to fetch fresh data from the internet. It’s quick, safe, and even beginners can do it.

Windows 11 / Windows 10

• Open an elevated Command Prompt: press Win + X, pick Windows Terminal (Admin).
• Run: ipconfig /flushdns.
• What to see: “Successfully flushed the DNS Resolver Cache.” That silent confirmation means the job’s done.

macOS (Ventura, Monterey, Big Sur)

Open Terminal, paste the command that matches your OS, enter your admin password when prompted. No message appears; the command completes quietly.

Linux (systemd‑resolved)

• Open a terminal.
• Execute: sudo systemd-resolve --flush-caches.
• Verify with systemd-resolve --statistics; the Cache entries should read 0.

Linux (nscd)

If your distro uses nscd, restart it:

• sudo systemctl restart nscd or sudo service nscd restart.

Android (Settings)

• Go to Settings → Network & Internet → Advanced → Reset Wi‑Fi, mobile & Bluetooth.
• Confirm; this resets adapters and clears DNS data.

Android (ADB – advanced users)

• Ensure ADB is installed and USB debugging is on.
• Run:

Copy
1adb shell ip -s -d -f inet neigh flush all
2  adb shell ip -s -d -f inet6 neigh flush all

iOS (13 +)

• Navigate to Settings → General → Reset → Reset Network Settings.
• This wipes DNS cache, Wi‑Fi passwords, and VPN configs.
• A quick reboot also forces a flush.

Quick‑Reference Table

Takeaway: Flushing DNS is like clearing a cluttered desk—everything gets fresh, organized, and ready for the next task. Ready to give your devices a clean slate? Try the steps above and feel the speed and security boost.