How to flush DNS: A complete guide for privacy and speed

What is a DNS flush?

Every time you type in a website, your device queries a DNS server to translate the domain name into a numeric IP address. To speed things up, your computer or phone stores those results locally in a DNS cache.

Over time, however, that cache can become outdated or corrupted. A DNS flush clears the stored entries, forcing your device to fetch fresh records. Think of it as refreshing the address book your system uses to find websites.

If you’re curious about how DNS plays into surveillance, see our explainer on who is tracking your internet activity.

Why flushing DNS improves privacy

Most people flush DNS to fix broken connections, but it also benefits privacy. Your DNS cache can act like a record of sites you’ve visited. While it’s not as obvious as browser history, malware or local attackers can still read it.

Flushing the cache wipes those traces and helps block DNS spoofing attacks that redirect traffic to malicious servers. Still, remember: a DNS flush only clears local history. Your ISP can still see live DNS queries unless you protect them with a VPN.

Learn more in our guide to DNS leaks.

This is where NymVPN stands out. Unlike standard VPNs that just encrypt DNS requests, Nym uses a Noise Generating Mixnet to hide both DNS content and metadata. That means observers can’t infer who you’re talking to or when—a major upgrade in privacy. See our full explanation of what a mixnet is.

DNS flush vs. changing DNS servers

It’s important not to confuse flushing DNS with changing DNS servers. Flushing clears cached entries; switching servers means pointing your device to a different resolver like Google DNS or Cloudflare.

Changing servers can improve speed, but it doesn’t guarantee privacy since those providers still log queries. The best defense is using a VPN with DNS leak protection.

How often should you flush DNS?

There isn’t a set rule, but it’s a good idea whenever you notice connectivity issues, after switching DNS servers, or if you want to erase traces of browsing from your device.

For privacy-minded users, flushing DNS periodically plus keeping NymVPN on at all times ensures you’re both cleaning old data and protecting new activity.

DNS flushing improves online privacy

Clearing your DNS cache is a simple but effective way to clean up browsing traces, resolve connection issues, and defend against spoofing attacks. While a DNS flush alone won’t make you invisible online, it’s a valuable step in reducing the digital footprints left on your device.

For stronger, ongoing protection, you need more than a manual cleanup. Pairing regular DNS flushes with privacy-first tools like NymVPN ensures that your DNS queries are encrypted, anonymized, and shielded from surveillance at the network level. With Nym’s mixnet technology, your metadata stays hidden, closing the privacy gaps traditional VPNs leave exposed.