MUTools

Whois Lookup

Whois Lookup retrieves registration info for domain names, URLs, and IP addresses in bulk. Enter one entry per line up to 10 entries, view results in a table, or download CSV. A raw-data (JSON) view is also available per row.

Entered 0 / 10
Press "Look up Whois" to see the result table here.

Lookups go through the IANA Bootstrap Registry directory. Each request times out after 8 seconds.

Unsupported TLDs / IP ranges are returned as error rows. Check the supported list from the button.

About Whois Lookup

Whois Lookup retrieves registration info for domain names, URLs, and IP addresses in bulk. Enter one entry per line up to 10 entries, view results in a table, or download CSV. A raw-data (JSON) view is also available per row.

The nine fields retrieved are registration date, last updated, expiry, days to expiry, domain age, name servers, domain status, registrar, and DNSSEC. With one click you can pull together everything needed for domain acquisition / renewal management, pre-transfer research, or confirming the managing organization for an IP address.

Beyond domains, you can paste a URL (with https://) or an IP address (IPv4 / IPv6). The tool auto-detects the domain part or IP and runs the right lookup.

How to use

  1. Paste the domain names, URLs, or IP addresses you want to look up — one per line, up to 10.
  2. Click "Whois lookup" — each entry is queried and the registration info appears in a table.
  3. The "Days to expiry" column shows the remaining days; the "DNSSEC" column shows whether DNSSEC is enabled.
  4. Toggle "Show Japanese header names" to switch the table and CSV headers to Japanese.
  5. Click "Download CSV" to save the full results for Excel / Sheets (UTF-8 + BOM).
  6. Each row's "Raw data (JSON)" button shows the underlying response for that entry.

Use cases

  • Information system or web admins checking expiries and days-to-expiry across the domains they manage.
  • Looking up the current registrar and name servers in one place when evaluating a domain transfer.
  • Individuals or companies quickly checking the registration status of domains they are considering buying.
  • SEO leads and marketers researching the registration date and age of competitor domains.
  • Security leads auditing DNSSEC adoption across a domain portfolio.

Notes

  • Up to 10 entries per request.
  • Each entry has an 8-second timeout — slow RDAP servers may error.
  • Some TLDs and IP ranges that lack RDAP support cannot be looked up. Errors like "TLD not supported by RDAP." may appear.
  • Domains using a privacy service may show a proxy registrant rather than the actual registrant.
  • IPv4 and IPv6 are supported, but private IPs (e.g., 192.168.x.x) are out of scope.

FAQ

How many entries can I process at once?
Up to 10 per request. Run multiple batches for larger jobs.
If I paste a URL, will the domain be extracted?
Yes. A URL like https://example.com/path/page is automatically reduced to the example.com domain and looked up.
Can I look up domains using a privacy service?
Lookups still succeed, but the registrant's name and address are replaced by the privacy proxy. Technical fields like registrar, expiry, and name servers are still returned as usual.
What columns does the CSV include?
Domain / IP, registration date, last updated, expiry, days to expiry, domain age, name servers, domain status, registrar, and DNSSEC — 10 columns. Enable "Show Japanese header names" to switch the headers to Japanese.
Some domains or IPs fail to look up.
Some TLDs and IP ranges still lack RDAP support — older ccTLDs especially. On those, please use the TLD's official whois page or another lookup tool.