Find IPs used by a domain across many DNS resolvers (DoH)

Queries multiple public resolvers via DNS-over-HTTPS (DoH), lists per-resolver answers, aggregates unique IPs, and can �ping� (HTTP/TCP reachability) each IP to see if services are up.



Tip: large CDNs may rotate answers each query.
Resolvers & DoH endpoints tried
Per-resolver results
Ping / Reachability checks (grouped by domain) Browser-safe (HTTP/TCP) or server proxy (ICMP/TCP)
Browser-only mode can�t do ICMP, but a successful opaque HTTP fetch still proves the service responded.
Aggregated unique IPs
Notes
  • This page prefers JSON DoH endpoints. Some providers block browser origins (CORS); those will show fetch errors. Use the server proxy below to avoid CORS.
  • �Ping� here means HTTP/TCP reachability from your browser. For real ICMP/TCP checks, enable the proxy.
  • HTTPS to a raw IP can fail due to certificate/SNI mismatch � that�s normal and doesn�t necessarily mean the host is down.
Optional server-side checker (Node.js)
Click to view (ICMP + TCP port checks; also acts as DoH CORS proxy) 
// server.js
// ICMP ping + TCP port check + DoH proxy to avoid CORS
const express = require('express');
const fetch = require('node-fetch');
const net = require('net');
const ping = require('ping'); // npm i express node-fetch ping
const app = express();

// CORS
app.use((_,res,next)=>{res.set('Access-Control-Allow-Origin','*'); next();});

// DoH proxy (optional)
app.get('/proxy', async (req,res)=>{
  const url = req.query.u;
  if(!url) return res.status(400).json({error:'missing u'});
  try{
    const r = await fetch(url,{headers:{'Accept':'application/dns-json'}});
    const txt = await r.text();
    res.set('Content-Type', r.headers.get('content-type')||'application/json');
    res.send(txt);
  }catch(e){ res.status(502).json({error:String(e)}) }
});

// ICMP + TCP check
app.get('/check', async (req,res)=>{
  const ip = req.query.ip;            // required
  const ports = (req.query.ports||'80,443').split(',').map(p=>parseInt(p,10)).filter(Boolean);
  if(!ip) return res.status(400).json({error:'missing ip'});

  // ICMP
  let icmp = null;
  try{
    const pr = await ping.promise.probe(ip,{timeout:2});
    icmp = {alive: pr.alive, time_ms: pr.time ? Number(pr.time) : null};
  }catch{icmp = {alive:null,time_ms:null}}

  // TCP ports
  async function checkPort(port, timeout=2000){
    return new Promise(resolve=>{
      const start = Date.now();
      const sock = net.createConnection({host:ip,port,timeout}, ()=> {
        const ms = Date.now()-start;
        sock.destroy();
        resolve({port, status:'open', time_ms:ms});
      });
      sock.on('timeout',()=>{sock.destroy(); resolve({port,status:'timeout',time_ms:timeout});});
      sock.on('error',err=>{resolve({port,status:err.code||'error',time_ms:null});});
    });
  }
  const tcp = await Promise.all(ports.map(p=>checkPort(p)));
  res.json({ip, icmp, tcp, when: new Date().toISOString()});
});

app.listen(3000,()=>console.log('Checker listening on :3000'));