Is my DNS change live yet?" is genuinely hard to answer from a single machine. Your own resolver might still be serving a cached answer while the rest of the internet has moved on — or vice versa. And "propagation" is a bit of a misnomer: nothing spreads outward from your nameserver. Your authoritative server updates instantly; every resolver that already cached the old value just keeps serving it until the TTL expires.
Built a checker that makes this actually observable:
- Queries Cloudflare, Google, and Quad9 — three independent public resolvers — at the same instant
- Checks A, AAAA, MX, TXT (incl. SPF), and NS records in one pass
- Flags any record where the resolvers disagree, which is the clearest live signal a change is still propagating
- NS-record visibility specifically for full nameserver migrations (IP records can look "done" while delegation is still catching up)
- Uses DNS-over-HTTPS since the serverless platform this runs on blocks outbound UDP on port 53
It's part of a broader Site Health Check — submitting also runs an SSL check, HTTP security header scan, and robots.txt validation on the same domain, all in parallel.
Free, rate-limited per IP (not paywalled), no signup.
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