Websites & Hosting

Who

Domain lookup and website monitoring with alerts for downtime, DNS shifts and expiring certificates.

Overview

Who looks up domain and website information, including WHOIS, RDAP, DNS, domain names, name servers and IPs. Its monitoring probes each domain live and sends alerts for downtime, DNS changes and certificates nearing expiry.

Updated Nov 13, 2026

5 things

What Who has

For developers

Programmatic access to the product's data and features for developers.
A Model Context Protocol server that lets AI tools connect to and act on your data. One of 17 Website & Hosting tools with MCP server.
A machine-readable description of an API's endpoints and request formats. One of 4 Website & Hosting tools with openAPI spec.

Support

Real people you can contact when you need help with the tool.

Extras

A collection of answers to common questions about using a product.

3 features

Key Features

Uptime check
Check whether a website is reachable right now.
Nameserver lookup
See which domains a given nameserver hosts.
Registrar directory
Browse domain registrars and the domains they manage.

Pros and cons

Pros

Live probes show what Who sees before it sends monitoring alerts.

You?

Be the first to rate Who

Your review helps others make better decisions. No account needed. Takes about 10 seconds.

4 questions

FAQs

What does Who do?

Who finds information about domains and websites. It also monitors domains and alerts you when a site goes down, DNS changes or a certificate nears expiry.

What information does the API return?

The API returns parsed WHOIS, normalized RDAP, and DNS and TLS certificate history for any domain as JSON over HTTPS.

What can Who support help with?

Support can help with privacy requests, orders, accounts and business inquiries about Who. It does not represent companies whose details appear in WHOIS records.

Where do Who's FAQ answers come from?

Answers come from Who guides and its FAQ, but they are AI-generated. Double-check anything important.

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Community reviews

Sort:Write a review

No written reviews yet. Be the first to share your experience.

Tried this tool? Share your experience.

Write a review

5 things

What Who has

For developers

Programmatic access to the product's data and features for developers.
A Model Context Protocol server that lets AI tools connect to and act on your data. One of 17 Website & Hosting tools with MCP server.
A machine-readable description of an API's endpoints and request formats. One of 4 Website & Hosting tools with openAPI spec.

Support

Real people you can contact when you need help with the tool.

Extras

A collection of answers to common questions about using a product.

3 features

Key Features

Uptime check
Check whether a website is reachable right now.
Nameserver lookup
See which domains a given nameserver hosts.
Registrar directory
Browse domain registrars and the domains they manage.

Pros and cons

Pros

Live probes show what Who sees before it sends monitoring alerts.

You?

Be the first to rate Who

Your review helps others make better decisions. No account needed. Takes about 10 seconds.

4 questions

FAQs

What does Who do?

Who finds information about domains and websites. It also monitors domains and alerts you when a site goes down, DNS changes or a certificate nears expiry.

What information does the API return?

The API returns parsed WHOIS, normalized RDAP, and DNS and TLS certificate history for any domain as JSON over HTTPS.

What can Who support help with?

Support can help with privacy requests, orders, accounts and business inquiries about Who. It does not represent companies whose details appear in WHOIS records.

Where do Who's FAQ answers come from?

Answers come from Who guides and its FAQ, but they are AI-generated. Double-check anything important.

Who

Overview

What Who has

For developers

Support

Extras

Key Features

Uptime check

Nameserver lookup

Registrar directory

Pros and cons

Pros

Be the first to rate Who

FAQs

What does Who do?

What information does the API return?

What can Who support help with?

Where do Who's FAQ answers come from?

What Who has

For developers

Support

Extras

Key Features

Uptime check

Nameserver lookup

Registrar directory

Pros and cons

Pros

Be the first to rate Who

FAQs

What does Who do?

What information does the API return?

What can Who support help with?

Where do Who's FAQ answers come from?

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