How to Clear and Debug DNS Cache in chrome://net-internals

Google Chrome, like most modern browsers, maintains its own DNS cache to speed up website loading and improve overall browsing performance. However, sometimes this cache can become outdated or corrupted, leading to issues such as websites not loading, slow browsing, or errors like �DNS_PROBE_FINISHED_NXDOMAIN.� When these problems occur, clearing and debugging the DNS cache using Chrome�s built-in Net Internals tool�accessible at chrome://net-internals/#dns�can resolve them efficiently. 

This knowledgebase article provides a comprehensive guide for users and IT professionals on how to clear and debug the DNS cache in Chrome.

What is DNS Cache and Why Does It Matter?

DNS (Domain Name System) cache is a local database maintained by your browser and operating system. It stores the IP addresses of recently visited websites, allowing Chrome to quickly resolve domain names without querying external DNS servers every time. This speeds up browsing and reduces network traffic.

However, if a website changes its IP address or there�s a misconfiguration, Chrome may continue to use outdated DNS entries, resulting in:

• Websites failing to load despite a working internet connection

• Errors like �DNS_PROBE_FINISHED_NXDOMAIN�

• Slow loading times for frequently visited sites

• Intermittent connectivity issues

Clearing the DNS cache forces Chrome to fetch fresh DNS records, often resolving these issues.

Accessing Chrome Net Internals

Chrome�s Net Internals tool is a powerful, built-in diagnostics utility that lets users inspect, manage, and clear network-related data�including DNS cache�directly from the browser.

To access Chrome Net Internals:

1. Open Google Chrome.

2. In the address bar, type chrome://net-internals/#dns and press Enter.

3. The DNS diagnostics page will open, displaying information about Chrome�s DNS cache and related settings.

Step-by-Step: Clearing DNS Cache in Chrome

1. Open the DNS Diagnostics Page

• Launch Chrome and navigate to chrome://net-internals/#dns.

• You�ll see a section called Host resolver cache which lists all stored DNS records.

2. Clear the Host Cache

• Locate the Clear host cache button on the page.

• Click Clear host cache.

• This action immediately flushes Chrome�s DNS cache, removing all stored domain records.

Tip: This process only clears the DNS cache for Chrome, not for your entire operating system. If issues persist, consider flushing your system�s DNS cache as well.

3. (Recommended) Flush Socket Pools

Chrome also maintains socket pools�active network connections that may retain outdated DNS information even after clearing the DNS cache.

• In the address bar, type chrome://net-internals/#sockets and press Enter.

• Click the Flush socket pools button.

• This closes all active connections, ensuring Chrome does not reuse old DNS data.

4. Restart Chrome

• After clearing the DNS cache and flushing socket pools, restart Chrome to ensure all changes take effect.

• Try reloading the problematic website.

Debugging DNS Issues with Net Internals

Clearing the DNS cache often resolves most browsing issues, but Chrome�s Net Internals tool also provides advanced debugging features.

Reviewing Active DNS Entries

• On the chrome://net-internals/#dns page, scroll down to the Host resolver cache section.

• Here, you can review all currently cached domain names and their resolved IP addresses.

• If you notice outdated or incorrect entries, clearing the cache as described above will remove them.

Diagnosing Persistent Issues

If problems persist after clearing the cache:

• Check whether the issue is limited to Chrome or affects other browsers.

• Try flushing your operating system�s DNS cache:

• Windows: Open Command Prompt and run ipconfig /flushdns

• macOS: Open Terminal and run sudo dscacheutil -flushcache

• Linux: Depending on your distribution, restart the DNS service (e.g., sudo systemctl restart nscd).

• Consider changing your DNS server settings to a public DNS provider for improved reliability (e.g., Google DNS: 8.8.8.8, Cloudflare DNS: 1.1.1.1).

Additional Troubleshooting Tips

• Disable Browser Extensions: Some extensions, especially those related to security or VPNs, can interfere with DNS resolution. Temporarily disable them to see if the issue resolves.

• Check for Network Issues: Ensure your internet connection is stable and not experiencing packet loss or high latency.

Why Use Chrome�s Net Internals Instead of System DNS Flush?

While flushing your operating system�s DNS cache can help, Chrome maintains its own DNS cache independently. This means that even after a system-level flush, Chrome might continue to use outdated DNS records until its internal cache is cleared. Using chrome://net-internals/#dns provides a more targeted solution for browser-specific issues.

When Should You Clear Chrome�s DNS Cache?

• After updating DNS records for a website you manage

• When you encounter persistent DNS-related errors in Chrome

• If websites load incorrectly or not at all, despite working in other browsers

• After changing network settings, VPNs, or switching between networks

Summary Table: Clearing and Debugging DNS Cache in Chrome

Frequently Asked Questions

Q: Will clearing Chrome�s DNS cache affect my browsing history or saved passwords?
A: No, clearing the DNS cache only removes stored domain name resolutions. Your browsing history, cookies, and saved passwords remain unaffected.

Q: Do I need to clear the DNS cache regularly?
A: It�s not necessary unless you�re experiencing DNS-related issues or have recently changed DNS records for a website you visit or manage.

Q: Can I automate DNS cache clearing in Chrome?
A: Chrome does not offer a built-in way to schedule DNS cache clearing. However, regularly restarting the browser or using developer tools can help manage cache issues.

Conclusion

Clearing and debugging the DNS cache in Chrome using chrome://net-internals/#dns is a straightforward yet powerful way to resolve many common browsing issues related to outdated or corrupted DNS records. By following the steps outlined above�clearing the host cache, flushing socket pools, and restarting Chrome�you can ensure your browser always fetches the latest DNS information, resulting in faster and more reliable website access.

If problems persist, consider flushing your system�s DNS cache or adjusting network settings. For most users and IT professionals, Chrome�s Net Internals tool is an essential resource for maintaining optimal browser performance and troubleshooting connectivity issues.

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