GitHub Pages custom domain DNS check unsuccessful despite correct DNS records

[noiwanwan]

🏷️ Discussion Type

Question

💬 Feature/Topic Area

Pages

Body

Hello,

I'm experiencing an issue with the custom domain configuration for my GitHub Pages website.

Repository: https://github.com/noiwanwan/shinomiya-works

Custom domain: shinomiya-works.com

Issue:
The GitHub Pages settings continue to display "DNS check unsuccessful" (previously showing InvalidDNSError), and HTTPS enforcement is not available.

DNS configuration:

A records for the apex domain:

185.199.108.153

185.199.109.153

185.199.110.153

185.199.111.153

CNAME for www:

noiwanwan.github.io

The DNS provider is XServer Domain.

The repository uses the main branch and publishes from the root directory. The CNAME file contains exactly:

shinomiya-works.com

Troubleshooting already performed:

[sknoyon324234234234]

I checked this from outside, and your DNS is fine. But there's one thing that doesn't match your description: the site is currently configured for www, not the apex.

• The CNAME file on main right now contains www.shinomiya-works.com (not shinomiya-works.com), and the Pages API also reports the custom domain as www.shinomiya-works.com.
• http://shinomiya-works.com → 301 → http://www.shinomiya-works.com/ → 200, so GitHub is serving the site on www and redirecting the apex to it.
• DNS: the apex has the four 185.199.108–111.153 A records, www is CNAME noiwanwan.github.io, no AAAA/CAA/DNSSEC. That's correct for either setup.
• The certificate hasn't been requested yet (https_certificate is empty), which is why Enforce HTTPS isn't available.

So it looks like the domain was switched between apex and www at some point. Each switch resets the DNS check and the certificate request. What I'd do:

1. Decide which one should be primary. If you want the apex, type shinomiya-works.com in Settings → Pages → Custom domain and save. That rewrites the CNAME file, so don't also edit it by hand.
2. Then leave it alone. The DNS check usually turns green within minutes to an hour once it's stable, and the certificate gets issued after that (it can take up to ~24h). Enforce HTTPS becomes clickable once it's done.

Either primary works with your DNS as it is; GitHub redirects the other one automatically.

[noiwanwan]

Thank you very much for your detailed investigation and helpful explanation!

I've now verified the DNS records using PowerShell.

Google DNS (8.8.8.8):

• shinomiya-works.com → All four GitHub Pages A records are returned correctly.
• www.shinomiya-works.com → CNAME points to noiwanwan.github.io.

Authoritative DNS server (ns1.xdomain.ne.jp):

• www.shinomiya-works.com → CNAME also correctly points to noiwanwan.github.io.

Based on your advice, I've decided to keep www.shinomiya-works.com as my primary domain.

I will leave the DNS and GitHub Pages settings unchanged for now and allow more time for DNS verification and HTTPS certificate provisioning.

If the issue persists after 24 hours, I'll post an update here.

Thank you again for taking the time to help me!

[sknoyon324234234234]

Sounds like a good plan! And it's already moving: the certificate request has started since then. The Pages API now shows the HTTPS certificate in progress (state dns_changed), covering both www.shinomiya-works.com and shinomiya-works.com, where before there was no certificate request at all. Once it's issued, the "Enforce HTTPS" checkbox becomes available. Tick it then, and you're done.

[noiwanwan]

Update: GitHub Pages DNS check still failing despite correct DNS records

Hello,

I would like to provide an update on my GitHub Pages custom domain issue.

Repository: https://github.com/noiwanwan/shinomiya-works

Current custom domain: "shinomiya-works.com"

Issue: GitHub Pages continues to show "DNS check unsuccessful" / "InvalidDNSError", and the HTTPS certificate is still being provisioned.

I have been troubleshooting this issue since October 15, 2026.

DNS configuration and verification

I have verified the following:

• A records: All four GitHub Pages IP addresses are configured and resolve correctly:
  • "185.199.108.153"
  • "185.199.109.153"
  • "185.199.110.153"
  • "185.199.111.153"
• AAAA records: All four GitHub Pages IPv6 addresses are configured and resolve correctly.
• www CNAME: Points to "noiwanwan.github.io" and resolves correctly.
• Nameservers: "ns1.xdomain.ne.jp", "ns2.xdomain.ne.jp", and "ns3.xdomain.ne.jp".
• GitHub domain verification TXT record: The record is publicly resolvable through both Google DNS ("8.8.8.8") and the authoritative XServer nameserver.
• CAA records: Google Public DNS returned a successful response with no CAA records found.

I also checked DNS propagation using whatsmydns.net.

Most tested locations return the correct GitHub Pages IP addresses and nameservers. Some locations show no result, but I have not observed any conflicting IP addresses or nameservers.

Recent changes

I changed the custom domain from "www.shinomiya-works.com" to "shinomiya-works.com".

The repository's "CNAME" file has also been updated to contain:

"shinomiya-works.com"

The GitHub Pages settings show the TLS certificate provisioning process at step 1 of 3.

When I reopen the Pages settings, the status initially shows "DNS Check in progress". After refreshing and waiting, it changes to "DNS check unsuccessful".

The website content is accessible, but HTTPS is not working correctly.

Questions

Could someone help me determine:

1. Why GitHub Pages reports "InvalidDNSError" even though the required DNS records resolve correctly?
2. Whether the certificate provisioning process is blocked by the DNS validation failure.
3. Whether there is any additional configuration issue I should check, or whether this requires investigation on GitHub's side.

I would prefer not to repeatedly change the DNS configuration or custom domain settings without identifying the underlying cause.

Thank you for your help.

[sknoyon324234234234]

Good news: it's done now 🎉 I just checked the Pages API, and your certificate shows approved with Enforce HTTPS: on for shinomiya-works.com. The AAAA records you added are GitHub's correct IPv6 addresses too. The "DNS check unsuccessful" message in the settings page can lag behind; refresh it and it should turn green. https://shinomiya-works.com should work now.

[noiwanwan]

Thank you so much for your help!

I'm glad to hear that the SSL certificate has been approved and HTTPS is now enabled.

I really appreciate you taking the time to check the DNS settings and GitHub Pages configuration. Your assistance was extremely helpful!

Thanks again!