Guides
What Is DNS and Does It Affect Speed?
DNS resolves domain names to IP addresses.
Cached answers can avoid a new lookup; an uncached or failed lookup can delay connection setup. Changing DNS does not increase your connection's capacity.
What DNS can affect
- Filtering: some DNS services optionally block domains associated with malware or adult content. This is not a complete security check of every page.
- Name resolution: a failed DNS lookup can prevent a connection by name. One failing website alone does not prove that your resolver caused the problem.
- Server selection: DNS answers can direct you to different content delivery servers, indirectly affecting performance. A resolver change therefore offers no guaranteed download-speed improvement.
Compare the query and the website separately
- Record the exact hostname, time, device, app and error. Distinguish waiting before a connection starts from a transfer that slows down after the page has opened.
- Compare several hostnames on the same device under similar network load. For DNS queries, use the same record type and note answers or errors. Repeat observations: cached answers and their remaining validity can change the result.
- Check the device DNS settings and the browser’s Secure DNS settings. A browser or a required VPN may use a different DNS service from a separate system lookup.
- If changes are permitted, save the original settings and follow the provider’s instructions on one device. Keep required filters and management policies. Repeat the same page checks and restore the original settings if problems appear; a day of browsing that feels faster is not proof of a DNS improvement.
On Windows, an optional comparison is nslookup -type=A HOST RESOLVER or nslookup -type=AAAA HOST RESOLVER. Replace HOST with the actual hostname and RESOLVER with the address of the specific DNS server you are allowed to query. The result checks DNS records, not download speed or successful website access. Ping measures a different exchange, not DNS query time.
Use this site’s DNS tool in context
Enter a domain or subdomain without a URL path and choose the record type. A requests IPv4 addresses; AAAA requests IPv6 addresses. Our tool queries DNS from our server. Its result does not test the DNS service used by your device or browser.
No answer for one record type does not mean that the whole domain is broken. Different valid answers can result from caches or content delivery choices. For support, record the hostname, type, time and exact error, and remove private addresses, credentials and other sensitive details before sharing.
Secure DNS encrypts DNS transport; it does not replace HTTPS or a firewall. Keep required VPN and family or workplace filtering rules. Choose settings based on repeatable observations and the rules that apply to your device.