How to Flush DNS Cache on Every Platform

Your computer, browser, and router all cache DNS responses to speed up repeated lookups. Most of the time, this caching is invisible and beneficial. But when DNS records change, caches can serve stale data, making it look like your update did not work or causing you to reach the wrong server.

Flushing your DNS cache forces your system to discard stored DNS responses and fetch fresh data from upstream resolvers. This guide covers how to flush the DNS cache on every major platform, when you should do it, and when flushing alone is not enough.

Why DNS Caching Exists

Every DNS lookup involves multiple network requests: your device queries a recursive resolver, which may query root servers, TLD servers, and authoritative nameservers. This process takes time, typically 20-100 milliseconds.

Caching eliminates this latency for repeated queries. When you visit a website, the resolved IP address is cached at multiple levels:

• Browser cache: Chrome, Firefox, Safari, and Edge all maintain their own DNS caches
• Operating system cache: Windows, macOS, and Linux cache DNS responses at the system level
• Router cache: Many home and office routers cache DNS responses for all devices on the network
• Recursive resolver cache: Your ISP or public DNS resolver (like 8.8.8.8) caches responses based on TTL

Each layer has its own cache, and flushing one does not clear the others. For a complete refresh, you may need to flush at multiple levels.

When to Flush DNS Cache

Flushing DNS is appropriate in these situations:

Flush DNS Cache on Windows

Windows 10 and Windows 11

ipconfig /flushdns

You should see: Successfully flushed the DNS Resolver Cache.

To verify the cache was cleared, you can view the current cache contents:

ipconfig /displaydns

After flushing, this should show very few or no entries.

Windows DNS Client Service Restart

If flushing alone does not resolve the issue, restart the DNS Client service:

net stop dnscache
net start dnscache

Flush DNS Cache on macOS

The command differs depending on your macOS version, but the following works on macOS Monterey, Ventura, Sonoma, and Sequoia:

sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

You will be prompted for your administrator password. There is no confirmation message, but the cache is flushed immediately.

Older macOS Versions

| macOS Version | Command | |---------------|---------| | Sequoia / Sonoma / Ventura / Monterey | sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder | | Big Sur | sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder | | Catalina / Mojave / High Sierra | sudo killall -HUP mDNSResponder | | Sierra | sudo killall -HUP mDNSResponder | | El Capitan | sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder |

Flush DNS Cache on Linux

Linux distributions use different DNS caching services. Identify which one you are running and use the corresponding command.

systemd-resolved (Ubuntu 18.04+, Fedora, Arch)

sudo systemd-resolve --flush-caches

Or on newer versions:

sudo resolvectl flush-caches

To verify:

sudo resolvectl statistics

The cache size should show 0 after flushing.

nscd (Name Service Cache Daemon)

sudo systemctl restart nscd

Or:

sudo nscd -i hosts

dnsmasq

sudo systemctl restart dnsmasq

No local caching

Some Linux configurations do not cache DNS locally at all. If you are not running systemd-resolved, nscd, or dnsmasq, there may be no local cache to flush. Your DNS queries go directly to the configured resolver.

Flush DNS Cache in Web Browsers

Browsers maintain their own DNS caches separate from the operating system. Flushing the OS cache does not clear the browser cache.

Google Chrome

Navigate to chrome://net-internals/#dns in the address bar and click "Clear host cache."

Also clear the socket pool at chrome://net-internals/#sockets by clicking "Flush socket pools." Persistent connections can bypass DNS even after cache clearing.

Mozilla Firefox

1. Open the hamburger menu and go to Settings
2. Search for "cache" in the settings search bar
3. Click "Clear Data" and select "Cached Web Content"

Alternatively, type about:networking#dns in the address bar to see cached DNS entries and use the "Clear DNS Cache" button.

Safari

Safari does not expose a DNS cache clearing option directly. Clearing the browser cache via Safari > Settings > Privacy > Manage Website Data removes cached resources but may not clear DNS. Flushing the macOS system DNS cache is the reliable approach for Safari.

Microsoft Edge

Navigate to edge://net-internals/#dns and click "Clear host cache," similar to Chrome.

Flush DNS Cache on Routers

Your router likely caches DNS responses for all devices on your network. Flushing it ensures every device gets fresh DNS data.

Most Consumer Routers

The simplest approach is to restart the router. Power it off, wait 10 seconds, and power it back on. This clears the DNS cache along with all other cached data.

Router Admin Panel

Some routers offer a DNS cache flush option in their web admin interface. Access it at 192.168.1.1 or 192.168.0.1 (varies by manufacturer) and look for DNS settings.

Enterprise Routers and Firewalls

Enterprise equipment like pfSense, Ubiquiti, or Cisco devices has specific DNS cache management commands. Consult your device's documentation for the correct procedure.

Complete DNS Cache Flush Checklist

For a thorough flush when troubleshooting a stubborn DNS issue:

When Flushing Is Not Enough

If you have flushed at every level and still see old DNS data:

• The upstream resolver has a stale cache: Switch to a different public resolver temporarily
• The record has not actually changed: Query the authoritative nameserver directly to confirm the update was applied
• Negative caching: If a record was queried before it was created, the NXDOMAIN response is cached. The SOA minimum TTL determines how long negative responses persist
• Application-level caching: Some applications cache DNS independently (Java, for example, caches DNS aggressively by default). Restarting the application may be necessary

Flushing DNS cache is a quick fix for stale resolution, but it is a diagnostic tool, not a solution. If you find yourself flushing caches regularly, the underlying issue is usually TTL misconfiguration or a lack of automated DNS monitoring that would catch problems at the source.