--- title: "RDAP vs WHOIS: How Domain Lookups Work in 2026" description: "WHOIS is being retired in favor of RDAP. Here is how the two protocols differ, why ICANN forced the switch, and how to query structured registration data at scale." url: https://webatla.com/blog/rdap-vs-whois --- [Home](https://webatla.com/) › [Blog](https://webatla.com/blog) › RDAP vs WHOIS: How Domain Lookups Work in 2026 Engineering # RDAP vs WHOIS: How Domain Lookups Work in 2026 M **Marina** · Jun 13, 2026 · 4 min read Share webatla engineering · 2026 WHOIS is being retired in favor of RDAP. Here is how the two protocols differ, why ICANN forced the switch, and how to query structured regi… For four decades, **WHOIS** was how you looked up who registered a domain. That era is ending. **RDAP** — the Registration Data Access Protocol — has replaced it as the standard, and as of 2025 registries are no longer required to run the legacy WHOIS service at all. Here's what changed, why it matters, and how to query registration data the modern way. ## What is WHOIS? WHOIS is a simple request/response protocol that dates to 1982 (RFC 812, later RFC 3912). You connect to a server on **port 43**, send a domain name, and get back a blob of text describing the registrant, registrar, key dates, and nameservers. It worked — but it was built for a different internet: - **Unstructured text.** Every registry formatted its output differently, so parsing was a perpetual game of regex whack-a-mole. - **No internationalization.** It was ASCII-oriented, and non-Latin registrant data was a mess. - **No standard access control.** All-or-nothing output collided badly with privacy law like GDPR. - **No standard discovery.** You had to already know each TLD's WHOIS server. ## What is RDAP? **RDAP** (RFCs 7480–7484, updated by 9082/9083) is the modern replacement. Same goal — registration data — but redesigned from the ground up: - **JSON over HTTPS.** Structured, predictable responses you can parse reliably. - **A standard query scheme.** Consistent URLs like `https://rdap.example/domain/example.com`. - **Bootstrapping.** IANA publishes a registry that tells you which RDAP server is authoritative for any TLD, so discovery is automatic. - **Differentiated access.** It's authentication-aware, so a registry can return more data to authorized users while showing the public a redacted view — the GDPR-friendly model. - **Internationalization and redaction** are first-class concerns, not afterthoughts. ## RDAP vs WHOIS: the key differences | | WHOIS | RDAP | | --- | --- | --- | | Format | Free-text | Structured JSON | | Transport | Port 43 (plaintext) | HTTPS | | Discovery | Manual, per registry | IANA bootstrap registry | | Access control | None | Standardized, auth-aware | | Internationalization | Poor | Built-in | | Status | Being retired | Current standard | ## Why the industry switched ICANN ratified RDAP as the successor to WHOIS and required gTLD registries and registrars to implement it. The decisive moment came in **2025**, when contracted parties were no longer obligated to operate the legacy port-43 WHOIS service — formally ending WHOIS's run for gTLDs. If you're still building on WHOIS text parsing, you're building on a deprecated foundation. ## How to query RDAP A lookup is just an HTTPS GET. To find the right server you can consult the IANA bootstrap file, or hit a router endpoint that resolves it for you: ``` curl -s https://rdap.org/domain/example.com | jq '{ domain: .ldhName, status: .status, registrar: (.entities[]? | select(.roles[]? == "registrar") | .vcardArray[1][1][3]), created: (.events[]? | select(.eventAction == "registration") | .eventDate) }' ``` Because the response is structured JSON, pulling a specific field — registration date, status, nameservers — is a one-liner instead of a fragile parser. ## Querying registration data at scale RDAP is ideal for one domain at a time. For *millions* of domains you run into two walls: **rate limits** and **per-TLD server quirks** — every registry runs its own endpoint, with its own throttling and redaction rules. That's the gap the [RDAP & WHOIS dataset](https://webatla.com/datasets/rdap-whois) fills. We resolve registration data across every active domain and ship it as normalized [JSONL](https://webatla.com/datasets) — registrar, key dates, status, and nameservers in a single consistent schema — so you can analyze the whole namespace without running a distributed crawler or babysitting rate limits. ## Frequently asked questions **Is WHOIS dead?** For gTLDs, effectively yes — RDAP is the required protocol and the port-43 mandate has ended. Some ccTLDs still run legacy WHOIS, but the direction of travel is one-way. **Is RDAP data different from WHOIS data?** It's the *same* registration data, exposed in a structured, access-controlled way. Public responses are often redacted for privacy; authenticated access can return more. **Can I bulk-download registration data?** Per-domain RDAP is rate-limited, so live bulk work is impractical. A prepared [dataset](https://webatla.com/datasets/rdap-whois) is the scalable route. **How do I find the RDAP server for a TLD?** Use IANA's bootstrap registry, or a router like `rdap.org` that resolves it for you. You can browse coverage by [TLD](https://webatla.com/tld). ## Work with registration data the modern way Stop parsing port-43 text. [Get the RDAP & WHOIS dataset →](https://webatla.com/datasets/rdap-whois) for structured registration data across every domain, or [see all datasets](https://webatla.com/datasets) to combine it with technologies, ranking, and DNS. ### Get the data behind this post The same JSONL we used to write this article, fresh daily exports going forward. Buy one of the datasets that covers it. [Get the RDAP & WHOIS dataset →](https://webatla.com/datasets/rdap-whois) [See all datasets](https://webatla.com/datasets) M **Marina** Data writer · webatla Writes the data-journalism behind the webatla datasets, domain trends, technology adoption and how the index is built. ## Keep reading Data, Websites Created Using Wix: 4.9M Live (2026) 8 min · Jul 11, 2026 ### [Websites Created Using Wix: 4.9M Live (2026)](https://webatla.com/blog/websites-created-using-wix) Data, Websites Made With Shopify: 2.85M Live Stores (202… 8 min · Jul 10, 2026 ### [Websites Made With Shopify: 2.85M Live Stores (2026)](https://webatla.com/blog/websites-made-with-shopify) Data, Websites That Use Cloudflare: 54.4M Live (2026) 8 min · Jul 9, 2026 ### [Websites That Use Cloudflare: 54.4M Live (2026)](https://webatla.com/blog/websites-that-use-cloudflare)