PageSpeed Unable to Resolve URL: How to Fix DNS_FAILURE
You paste your URL into PageSpeed Insights, hit Analyze, and get this instead of a score: “Lighthouse returned error: DNS_FAILURE. DNS servers could not resolve the provided domain.” PageSpeed Unable to Resolve URL: Your site opens fine in your browser, which makes it more confusing. When PageSpeed is unable to resolve a URL, the problem is seldom your website’s code. It’s your domain’s DNS. Finding the cause usually takes a few minutes. The fix itself is often instant, though some DNS changes can take a few hours to reach Google’s servers.
What Does “Unable to Resolve URL” Mean in PageSpeed Insights?
It means Google’s test servers could not translate your domain name into an IP address, so Lighthouse never reached your server at all. This is a DNS lookup failure, not a performance problem.
That distinction matters. Images, plugins, hosting speed, and caching have zero effect here, because the test fails before a single byte of your page loads. Any time spent tweaking WordPress settings is wasted until DNS is fixed.
Why Does Your Site Load for You but Fail in PageSpeed?
Your computer and your internet provider cache DNS answers. If you changed hosts yesterday, your browser may still be using an old, working answer while the public internet sees something broken.
There’s a second reason that’s easy to miss. Google’s public DNS checks DNSSEC (a security layer for DNS records) strictly, and some home and mobile networks don’t. So a broken DNSSEC setup can work on your connection and still fail everywhere Google looks. A misconfigured DNSSEC setup can therefore work on your home connection and fail everywhere Google looks. A local hosts-file entry, common during site migrations, creates the same illusion.
Common Causes of the PageSpeed DNS_FAILURE Error
These are the causes I run into most often. Find the row that matches your situation before changing anything else.
| Cause | How to spot it | Fix |
| Typo or wrong subdomain | The URL has a misspelling, or you tested www when only the bare domain exists (or the reverse). | Copy the URL straight from the browser address bar and test again. |
| Missing A/AAAA or CNAME record | dig returns nothing for that hostname, even on public resolvers. | Add the record at your DNS provider, pointing to your host’s IP or target. |
| DNS change still propagating | You changed nameservers or records in the last 24 to 48 hours. | Wait, then flush the Google Public DNS cache for your domain. |
| Broken DNSSEC | Public resolvers return SERVFAIL, but the same lookup with +cd works. | Remove the old DS record at your registrar, or add the correct new one. |
| Expired domain or dead nameservers | WHOIS shows expiry, or NS records point to an old host you left. | Renew the domain and point nameservers to your current DNS provider. |
| Staging or internal-only URL | The site lives on localhost, a hosts-file entry, or a private network. | Test a public URL, or run Lighthouse locally in Chrome DevTools. |
How to Fix PageSpeed “Unable to Resolve URL” Step by Step
Step 1: Confirm the exact URL
Copy the address directly from your browser bar, including https:// and the correct subdomain. Testing www.example.com when only example.com has a DNS record is one of the most common reasons for this error.
Step 2: Look up your domain from outside your network
Run these commands in a terminal. The first uses your local resolver; the second asks Google Public DNS directly:
dig +short blog.example.com Adig @8.8.8.8 blog.example.com AOn Windows, dig isn’t installed by default. Use PowerShell instead:
Resolve-DnsName blog.example.com -Type A
Resolve-DnsName blog.example.com -Type A -Server 8.8.8.8
If the Google query returns no IP address, the record is missing or not yet visible. Not comfortable with the terminal? The web tool at dns.google gives the same answer in a browser.
Step 3: Rule out DNSSEC
If the Google query returns SERVFAIL, repeat it with the +cd flag, which turns off DNSSEC checking:
dig @8.8.8.8 blog.example.com A +cdAn IP address on this second query confirms DNSSEC is the problem. This typically happens after moving to a new DNS provider such as Cloudflare while the registrar still holds the old DS record. Delete the old DS record, or replace it with the one your new provider gives you. DNSViz (dnsviz.net) will show exactly where the signature chain breaks.
Step 4: Wait out propagation, then flush Google’s cache
Record changes usually appear within a few hours; nameserver changes can take up to 48. Once your records look correct, use the Google Public DNS Flush Cache tool to clear the stale answer for your domain.
Step 5: Retest in PageSpeed Insights
Run the test again. If you now get a different error, that’s progress: it means DNS works and the issue has moved further down the connection.
What I’ve Seen in Practice
The first time I ran into this was on my own WordPress site, gadgetcrunchie.com. The site opened fine in my browser, but PageSpeed Insights kept saying it was “Unable to resolve URL.” Once I worked through the DNS side, the error disappeared, and PageSpeed tested the site normally. That’s the main reason I wrote this guide: the error looks like your website is broken, but the site itself was never the problem.
I’ve since moved my own blog to a subdomain and my main site to Cloudflare, and both times the lesson was the same. When a DNS record seems “stuck”, it’s usually an old record nobody deleted, not a slow propagation delay. Check for leftovers before you wait 48 hours.
DNS_FAILURE vs FAILED_DOCUMENT_REQUEST: Which Error Do You Have?
These errors look similar but have different causes, and mixing them up sends you in the wrong direction.
- DNS_FAILURE: Google could not find your server’s IP address. Fix your DNS.
- FAILED_DOCUMENT_REQUEST: Google found your server, but the connection failed or timed out. Check firewalls, security plugins, and bot-protection rules that may block Google’s test servers.
- ERRORED_DOCUMENT_REQUEST: Your server responded with an error status such as 403 or 404. Check the page itself and your server rules.
Frequently Asked Questions
Get Your PageSpeed Test Working Again
Start with Step 2: one dig query against 8.8.8.8 tells you within seconds whether you’re dealing with a missing record, slow propagation, or broken DNSSEC. Once PageSpeed can reach your site, the real work starts: improving your Core Web Vitals. My Core Web Vitals guide covers the thresholds and the fixes. If you’d rather hand it off, I offer technical SEO and speed fixes, and I fix the issues instead of just reporting them.
