Here is the list of the top 10 most popular and used Free Whois Tools on the internet. Whois is a widely used Internet record listing that identifies who owns a domain and how to get in contact with them. The Internet Corporation for Assigned Names and Numbers (ICANN) regulates domain name registration and ownership.[source]
All the listed Whois Tools below is valid for kinds all domain or website extensions like .COM, .NET, .ORG and more. Some Whois Lookup tool will not provide the needed information or just only valid for if they are the registrar of that particular domain. Others are exclusively functioning for a particular domain extension only like .EDU, .AU, .CA, and more.

Table of Contents:
👉 ICANN Lookup
👉 Whois.com
👉 Who.is
👉 Domain Tools
👉 MXToolbox
👉 Tucows
👉 Domain.com
👉 EuroDNS
👉 Name.com
👉 Alibaba Cloud

Top 10 WHOIS Tools for domain information search

Note: This post only tackles the most used Whois Tools on the internet and the items are not in any particular order or ranking.

👉 ICANN Lookup
ICANN plays a unique role in the infrastructure of the internet. Through its contracts with registries (such as dot-com or dot-info) and registrars (companies that sell domain names to individuals and organisations), we help define how the domain name system functions and expands.
A ICANN Lookup tool simply provides the following:
☑ Domain Information
☑ Contact Information
☑ Registrar Information
☑ DNSSEC Information
☑ Autoritative Servers
☑ Notices and Remarks
☑ Raw Registry/Registrar RDAP Responses.
You can try the tool here: ICANN Lookup

👉 WHOIS Lookup
According to the site, they are the world's most affordable online identity provider.
Whois.com Whois Tool provides the following:
☑ Domain Information
☑ Registrant Contact
☑ Raw Whois Data
You can try the tool here: WHOIS Lookup

👉 WHO.IS
There is no "About" page for this website but see what they provide regarding the Whois Tool below.
Who.is Lookup tool provides the following:
☑ Registrar Info
☑ Important Dates (about domain)
☑ Name Servers
☑ Similar Domains
☑ Registrar Data
☑ DNS Records
☑ Diagnostics
You can visit the tool here: Who.is

👉 DOMAINTOOLS
DomainTools takes indicators from your network, including domains and IPs, and connects them with nearly every active domain on the internet. These connections help security professionals profile attackers, guide online fraud investigations, and map cyber activity to attacker infrastructure.
DomainTolls Whois provides:
☑ Domain Profile (contains Registrant, Registrar, Name servers, Contact)
☑ Whois Record
You can try the tool here: DomainTools

👉 MXToolbox.com
Their tool will return WHOIS registration results for a DOMAIN name.  Depending on the registrar, you can see various information like who is it registered to, when it was registered and when it expires, where the DNS is hosted, and more.  In some cases, you will be able to go the registrar's site to get more information.
The tool provides:
☑ Registrar
☑ Name Server
☑ Domain info
☑ DNSSEC
Try the MXToolbox here: https://mxtoolbox.com/Whois.aspx

👉 Tucows Domains Whois
Tucowsdomains Whois search provides the following:
☑ Contact details for the domain owner
☑ Domain name servers (DNS)
☑ Status of the domain
Try tool here: Tucowsdomains

👉 Domain.com Tool
WHOIS Lookup results will reveal who or what entity owns or manages that domain name, including their contact information such as name, phone number and address.
The tool will provide the following:
☑ Domain name
☑ Registrar
☑ Reseller
☑ Registrant
☑ Contact info
☑ Name server

👉 Eurodns.com Tool
The tool will provide the following:
☑ Domain name
☑ Registrar
☑ Reseller
☑ Registrant
☑ Contact info
☑ Name server
Try the tool here: Eurodns

👉 Name.com Tool
The tool will provide the following:
☑ Domain name
☑ Registrar
☑ Reseller
☑ Registrant
☑ Contact info
☑ Name server
Try the tool here: Name.com Tool

👉 Alibaba Cloud Whois Tool
The tool provides the following details:
☑ Registrant E-mail
☑ Sponsoring Registrar
☑ Registration Date
☑ Expiration Date
☑ Domain Status
☑ DNS Server
☑ Detailed WHOIS information
Try the tool here: AlibabaCloud