When in doubt, check DNS. When not in doubt, check DNS anyway. This site exists to help you debug DNS issues faster, with better tools, and maybe a smile.
"It's not DNS"
"There's no way it's DNS"
"It was DNS"
— Every developer, ever
DNS records get cached everywhere—your browser, OS, router, ISP, and CDN. You made the change 10 minutes ago, but the rest of the internet is still living in the past.
Set your TTL to 60 seconds? Cool. Some resolver out there is going to cache it for 24 hours anyway. DNS is more like polite suggestions than strict rules.
Changed your nameservers? Great! Now wait up to 48 hours for the internet to notice. DNS propagation is like telling a secret in a room full of people who might not be listening.
A records, AAAA records, CNAME records, MX records, TXT records, SPF, DKIM, DMARC, CAA... One typo, one missing dot, and your entire domain disappears into the void.
We're not alone in this struggle. These folks have been preaching the DNS gospel for years:
Every DNS debugging tool you'll ever need, organized by category. Bookmark this page.
Master the command line tools that every developer should know. Learn how to query DNS records, trace resolution paths, and understand what's actually happening under the hood.
Sometimes you need a GUI. Sometimes you need to check from multiple locations. Here are the best web-based DNS tools for every debugging scenario.
Why does DNS propagation take so long? What's actually propagating? And how can you speed it up? Let's demystify one of the most frustrating parts of DNS.