WhereIsDNS API

WhereIsDNS exposes a single public endpoint that returns DNS lookup results from 12 public resolvers as a Server-Sent Events (SSE) stream. It's the same endpoint the website itself uses. No signup, no auth.

GET /api/lookup

Query parameters:

host — the fully-qualified domain name to look up (e.g., example.com). Required.
type — DNS record type. One of A, AAAA, CNAME, MX, NS, TXT, SOA, CAA, PTR. Defaults to A.

Response: text/event-stream. One data: event per resolver as each settles, then a final {"done": true, "consensus": {...}} event when all 12 finish (or time out at 5 s).

Example

Request:

curl -N "https://whereisdns.com/api/lookup?host=example.com&type=A"

Stream (one event per line, abridged):

data: {"resolver":"Cloudflare","location":"Global","status":"ok","records":["104.20.23.154","172.66.147.243"],"latencyMs":42}
data: {"resolver":"Google","location":"USA","status":"ok","records":["104.20.23.154","172.66.147.243"],"latencyMs":58}
...
data: {"resolver":"Quad9","location":"Switzerland","status":"timeout"}
data: {"done":true,"consensus":{"104.20.23.154, 172.66.147.243":11,"NXDOMAIN":0}}

Per-event fields

resolver — operator name (Cloudflare, Google, Quad9, …)
location — operator's nominal jurisdiction
status — "ok", "nxdomain", "timeout", or "error"
records — array of strings (only when status === "ok")
latencyMs — round-trip ms for ok/nxdomain results
message — error description (only when status === "error")

Final event

done: true — signals end of stream
consensus — object mapping each unique result string (sorted, comma-separated for multi-record results) to a count of resolvers reporting that result. NXDOMAIN counted separately.

Rate limits

No published rate limit at the moment. Reasonable use is fine; abusive automation will be blocked. If you need higher volume or guaranteed throughput, please open an issue.

Other endpoints

GET /api/health — returns ok (200). Use for uptime probes.

Source

The full implementation is on GitHub. It's a Cloudflare Worker fanning out DNS-over-HTTPS queries; the wire-format codec and resolver list live in worker/.