macos clear dns cache

3 min read 01-10-2024

Clearing your DNS cache on macOS can resolve issues related to website loading and network connectivity. Whether you’re a web developer troubleshooting problems or just an everyday user wanting to maintain your system, understanding how to clear your DNS cache is invaluable.

What is DNS Cache?

DNS (Domain Name System) cache is a temporary database maintained by your operating system that stores records of all recent visits and attempted visits to websites and other internet resources. This cache speeds up the process of loading websites by remembering the IP addresses associated with the domain names you’ve visited. However, sometimes this cache can become outdated or corrupted, leading to problems such as the inability to access websites, incorrect site loading, or issues after a domain name change.

Why Clear DNS Cache?

You might consider clearing your DNS cache for several reasons:

Website Issues: If a website has recently changed its DNS records and you’re unable to access it, clearing the DNS cache can help.
Network Problems: Users may experience connectivity issues that can often be resolved by refreshing the DNS cache.
Privacy Concerns: Clearing the cache can help remove traces of previously visited websites for privacy reasons.

How to Clear DNS Cache on macOS

Step-by-Step Instructions

Depending on your macOS version, the commands to clear the DNS cache may vary. Here’s how to do it:

Open Terminal: You can find Terminal by searching for it in Spotlight (Command + Space) or by navigating to Applications > Utilities > Terminal.
Enter the Command: Type the appropriate command for your macOS version and hit Enter. Here are the commands for some common macOS versions:
- macOS Monterey (12) or later:
```
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
```
- macOS Big Sur (11):
```
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
```
- macOS Catalina (10.15):
```
sudo killall -HUP mDNSResponder
```
- macOS Mojave (10.14):
```
sudo killall -HUP mDNSResponder
```
- macOS High Sierra (10.13):
```
sudo killall -HUP mDNSResponder
```
- macOS Sierra (10.12):
```
sudo killall -HUP mDNSResponder
```
Authenticate: You may be prompted to enter your administrator password.
Verify: You won’t receive any confirmation message, but you can verify the cache has been flushed by testing if the DNS issues have been resolved.

Additional Considerations

Restart Your Browser: After clearing the DNS cache, it may be beneficial to close and reopen your web browser to ensure it pulls the latest data from the DNS server.
Reboot Your Device: In some cases, a simple restart of your macOS device can help in ensuring all changes are properly applied.
Use a Different DNS Server: If DNS issues persist, consider switching to a public DNS service like Google Public DNS (8.8.8.8 and 8.8.4.4) or Cloudflare DNS (1.1.1.1) for potentially improved resolution times and reliability.

Common Questions from the Community

Here are a few relevant discussions from Stack Overflow regarding DNS cache on macOS:

Q: What does flushing the DNS cache do?

A: Flushing the DNS cache clears all the entries stored in the DNS cache, essentially forcing the operating system to retrieve new IP addresses from the DNS server for domain names. This can resolve issues where the IP addresses have changed but the cache still holds the old information. (Original author: william b)

Q: How can I tell if my DNS cache has been flushed?

A: While there is no direct confirmation after the cache is cleared, you can try accessing a recently changed website. If it loads correctly, it’s likely the cache was successfully flushed. Additionally, using tools like dig or nslookup from the Terminal can help confirm if the updated DNS records are now being resolved. (Original author: jonathan s)

Conclusion

Clearing the DNS cache on macOS is a simple yet effective way to troubleshoot and resolve various internet connectivity issues. Whether you’re facing difficulties accessing specific sites or need to ensure privacy, the command-line instructions outlined in this article will help you navigate the process seamlessly. Remember to use the latest macOS version commands and consider additional network adjustments if problems persist. Keeping your DNS cache clean can ensure a smoother browsing experience in the long run.

Additional Resources

For more information on DNS and how it works, check out Cloudflare's explanation of DNS.
To explore DNS testing tools, visit DNS Checker for real-time verification of DNS changes.

By following this guide, you'll be well-equipped to handle DNS-related issues on macOS and maintain efficient internet usage.