DNS propagation is the time it takes for DNS changes to be reflected across all DNS servers worldwide. When you update a DNS record (e.g., changing your website's IP address), the new value must be communicated to all recursive resolvers and authoritative servers. Due to caching and TTL (Time-To-Live) values, some resolvers may continue to serve the old record until the TTL expires and they fetch the updated version.

Propagation can take anywhere from a few minutes to 48 hours, although most changes are visible within a few hours. The speed depends on the TTL setting of the record and how quickly intermediate DNS servers refresh their caches. Lower TTL values speed up propagation but increase query load.

Each public DNS resolver (like Cloudflare, Google, Quad9) maintains its own cache and may have fetched the record at different times. If a recent change was made, some resolvers might still have the old cached record while others already have the new one. That’s exactly the reason this tool exists — to compare results and determine if propagation is complete.

TTL (Time-To-Live) is a value in seconds that tells DNS resolvers how long they can cache a DNS record before they must check for an update. A typical TTL is 3600 seconds (1 hour). Lower TTLs mean changes propagate faster but can increase the number of queries your authoritative server receives.

You cannot force all resolvers to update immediately, but you can: 1) Lower the TTL value before making changes (so the old record expires sooner), 2) Flush your local DNS cache, 3) Clear your browser cache, 4) Use a global DNS checker like this one to monitor when propagation has completed.

We query several popular public DNS services via DNS-over-HTTPS (DoH): Cloudflare (1.1.1.1), Google (8.8.8.8), Quad9 (9.9.9.9), and OpenDNS. Because of browser security restrictions (CORS), some resolvers may be unreachable from your location; they will be marked as “Error”. All queries are performed directly from your browser—no data is stored.