QAS Domain Checker – WHOIS RDAP

QAS Domain Checker adds a simple form to any page or post where visitors can check whether a domain is available, using RDAP — the modern, IANA-recommended replacement for the legacy WHOIS protocol.

You can try it live before installing: Live demo

Unlike other domain-checking plugins, this one is designed to be genuinely simple:

• One single result, inline. No separate « search », « results » and « details » pages to configure — insert the block or shortcode and it just works.
• Built for multilingual sites. Fully internationalized (i18n-ready) with all strings translatable. Once published, translations — including Spanish, Catalan, English, French and Portuguese — can be contributed by anyone via translate.wordpress.org, WordPress’s own community translation platform. The plugin also includes an option to force a specific language for the widget regardless of the page’s language.
• No build tools required to maintain. The block editor script is plain JavaScript — no Node, npm or webpack pipeline involved.
• Privacy-conscious. Only the domain name you search for is sent to the RDAP servers. No personal data is transmitted or stored. See « External services » below for full details.

What you get for each domain

• Availability status (available / already registered)
• Registrar name
• Registration and expiration dates
• Last changed date
• Last update of the RDAP database
• Name servers (DNS)
• Domain status codes (e.g. transfer/update/delete lock)
• DNSSEC status

How to use it

Block editor: search for « Comprobador de dominio » (Domain Checker) in the block inserter, add it to any page or post, and optionally set an accent color from the block sidebar.

Shortcode: add [qasdrw_domain_checker] to any page, post, or widget area that supports shortcodes.

Settings

Under Settings → Comprobador de dominios you can configure:

• How long a result is cached before querying the RDAP server again (0 to disable caching)
• Whether to force a fixed language for the widget
• A list of TLDs to exclude from lookups
• Whether to show a small, optional attribution link to QAS Solutions below the form (disabled by default; uses rel="nofollow" and requires explicit opt-in from the site administrator)

External services

This plugin connects to external services, exclusively to provide the domain-checking functionality that is the plugin’s core purpose. No connection is made unless a visitor actively submits a domain to check (or, for the IANA bootstrap file, periodically in the background to keep the list of supported TLDs up to date).

IANA RDAP Bootstrap Service

• What it is: the official Internet Assigned Numbers Authority (IANA) service that publishes the list of top-level domains (TLDs) and their corresponding RDAP servers.
• URL: https://data.iana.org/rdap/dns.json
• What is sent: no personal or site-identifying data. The plugin downloads a public, static JSON file.
• When: when the locally cached copy is missing or older than 7 days (cache duration is filterable by developers via qasdrw_bootstrap_cache_ttl).
• Terms of service: https://www.icann.org/en/data-protection/terms-of-service (IANA is operated by Public Technical Identifiers, an affiliate of ICANN, which publishes these terms on ICANN’s site)
• Privacy policy: https://www.icann.org/en/data-protection/privacy-policy

RDAP servers operated by domain registries

• What it is: the RDAP server responsible for the TLD being queried. The specific server contacted depends entirely on which domain the visitor searches for, since each TLD is operated by a different registry. The most common case by far is Verisign, the registry operator for .com, .net, .name and .cc — for example, a search for « example.com » contacts https://rdap.verisign.com/com/v1/domain/example.com.
  • Verisign Terms of Use: https://www.verisign.com/legal-center/terms-of-use/
  • Verisign Privacy Statement: https://www.verisign.com/legal-center/privacy/
• For any other TLD (e.g. .org, .es, .dev, or any of the hundreds of other existing extensions), the request goes to that TLD’s own registry operator instead — there are too many operators to list individually here, so to find out which organization operates a specific TLD and review its own policies, look it up in IANA’s root zone database at https://www.iana.org/domains/root/db, which links to each registry’s own website.
• What is sent: only the domain name entered by the visitor (e.g. « example.com »). No personal data, IP address logging, or identifying information is added by the plugin.
• When: only when a site visitor actively submits the domain-check form.

Query results are cached locally (using WordPress transients) for a configurable duration (1 hour by default) to reduce the number of requests sent to these external services.