To find out if a domain is locked, you will have to do a domain registration data search. Depending on the domain extension, you will have to use one tool or another.
-If you want to know about a generic domain (.com, org, .net, .info...) you can use the search engine of ICANN itself, the official organization responsible for the administration and coordination of domain names. To do so, click here.
-For domains with .es extension, you will have to do it through .es domains. To consult it, click click.
-The foundation of .cat domains also has its own search engine. You can check it by clicking here.
If the domain is locked, it will show the status 'clientTransferProhibited' as we can see below in the following search for registration data of the domain swmanuales.com:
Domain Name: swmanuales.com
Registry Domain ID: 2551392493_DOMAIN_COM-VRSN
Registrar WHOIS Server: whois.serveisweb.com
Registrar URL: http://www.serveisweb.com
Updated Date: 2022-04-28T17:53:05Z
Creation Date: 2020-08-07T06:35:04Z
Registrar Registration Expiration Date: 2022-08-07T06:35:04Z
Registrar: SW HOSTING & COMMUNICATIONS TECHNOLOGIES, S.L.
Registrar IANA ID: 1407
Registrar Abuse Contact Email: [email protected]
Registrar Abuse Contact Phone: +34.972010550
Domain Status: clientDeleteProhibited https://icann.org/epp#clientDeleteProhibited
Domain Status: clientTransferProhibited https://icann.org/epp#clientTransferProhibited
Domain Status: clientUpdateProhibited https://icann.org/epp#clientUpdateProhibited
If it is locked, you will not be able to transfer it to another registrar, as this is a measure to prevent it.