Online Tool Store
IP To Hostname
Look up an IP address's reverse-DNS hostname with a real PTR query via a public DNS-over-HTTPS resolver, with input validation and a clear result layout.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
How it works
- Enter an IPv4 address.
- Click "Look up hostname" to send a real PTR query to Cloudflare's public DNS-over-HTTPS resolver.
- See the hostname that comes back, or an honest "no PTR record found" if that IP doesn't have one configured.
FAQ
Does this perform a real reverse-DNS lookup?
Yes — it sends a real PTR query to Cloudflare's public DNS-over-HTTPS resolver (1.1.1.1) and shows whatever record comes back.
What is a reverse-DNS lookup?
It looks up the hostname associated with an IP address — the reverse of a normal DNS lookup, which goes from hostname to IP.
Why might an IP have no hostname?
Not every IP has a PTR (reverse-DNS) record configured — many residential and cloud IPs simply don't have one set up, so "No PTR record found" is a normal, accurate result for those.
Why does this use Cloudflare specifically?
Cloudflare's DNS-over-HTTPS JSON API is one of the few public resolvers that sets CORS headers allowing a browser page to query it directly — most DNS infrastructure isn't reachable this way, since DNS is normally a very different protocol than HTTP.
How we compare
| Feature | Online Tool Store | Command-line nslookup | Other online DNS tools |
|---|---|---|---|
| No terminal required | ✓ | ✗ | ✓ |
| IP validation before lookup | ✓ | ✗ | ✓ |
Results come from Cloudflare's public resolver, which may occasionally differ from what your own ISP's resolver returns — for a second opinion, `nslookup 8.8.8.8` from a terminal remains a reliable cross-check.