# 2s.io, free: Domain WHOIS API

> Modern WHOIS via RDAP. Query: domain (e.g. example.com). [...] GDPR: registrant personal data is generally redacted upstream and not returned.

2s.io's Free trial plan for the domain WHOIS API costs $0.00 per 1,000 domains. We check each provider's docs for 9 fields. 2s.io's docs list 5: Registrar, Name servers, Statuses, DNSSEC, Abuse contact.
2s.io limits how many calls you get but gives no number.
In [our domain WHOIS API benchmark](https://datacircle.dev/best-domain-whois-api.txt), the best plan from 2s.io scores 36.2 out of 100. 2s.io ranks 22nd of 24 providers.
This plan is free. We rank 495 plans for domain WHOIS APIs by price. Half the plans cost $1.575 or less per 1,000 domains. [See the best free domain WHOIS API plan.](https://datacircle.dev/best-domain-whois-api.txt)
[Searchwire's $10 pack](https://datacircle.dev/domain-whois-apis/searchwire/10-pack/llms.txt) is the cheapest paid plan per 1,000 domains. Searchwire's domain WHOIS API costs nothing beyond the plan price. [C99.nl's $25 yearly plan](https://datacircle.dev/domain-whois-apis/c99-nl/25-yearly/llms.txt) costs the least for 10,000 domains a month: $2.08.
[WhoisJSON](https://datacircle.dev/domain-whois-apis/whoisjson/120-monthly/llms.txt), [Enterno](https://datacircle.dev/domain-whois-apis/enterno/free-open-api/llms.txt) and [IPAddress.to](https://datacircle.dev/domain-whois-apis/ipaddress-to/free/llms.txt) are the best domain WHOIS API providers in the Datacircle benchmark.

- This page: https://datacircle.dev/domain-whois-apis/2s-io/free
- [Domain WHOIS API in 2026: the best of 20+ providers compared](https://datacircle.dev/best-domain-whois-api.txt)
- Get it: https://2s.io/catalog.txt?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- Request: `GET https://2s.io/api/domain/whois`
- API key: not needed
- Its API docs: https://2s.io/domain/whois?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- Sold by: 2s.io (https://2s.io?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing)
- Checked: 2026-11-09

## In the answer

- Completeness: 56%
- Registrar: ✓
- Name servers: ✓
- Statuses: ✓
- DNSSEC: ✓
- Abuse contact: ✓

## Price

- $ per 1,000 domains: $0.00
- Per: call
- Billing: free

## Charges

- Also pays for: nothing else

## Not found

- $ per 1,000: $0.00

## In their words

- Their pitch: Modern WHOIS via RDAP. Query: domain (e.g. example.com). [...] GDPR: registrant personal data is generally redacted upstream and not returned.

## Data

- Keep data: no API terms
- Use data: no API terms

## Plan

- Pay: $0

## Rate limit

- Per second: 0.00028
- Batch: 1

## Speed

- Answer: in the call
- Median: 0.03 s

## The call

- You send: domain
- Method: GET
- Path: /api/domain/whois

## About the plan

- Plan: Free trial
- Who can get it: anyone, with no wallet or payment, for one call per endpoint per hour (a request with ?trial=1 or the X-2s-Trial: 1 header)

## The 15 fields the plan's answer can hold

domain, LDH name, handle, registrar, registrar IANA ID, registrar URL, registrar abuse email, registrar abuse phone, registered at, expires at, updated at, statuses, nameservers, DNSSEC signed, RDAP URL

## 2s.io's plans (2)

- [2s.io, free](https://datacircle.dev/domain-whois-apis/2s-io/free/llms.txt): $0.00 per 1,000, 56% complete
- [2s.io, pay as you go](https://datacircle.dev/domain-whois-apis/2s-io/pay-as-you-go/llms.txt): $2.50 per 1,000, 56% complete

## 2s.io's calls for this API (1)

- `GET /api/domain/whois`: [2s.io, free](https://datacircle.dev/domain-whois-apis/2s-io/free/llms.txt)

## 2s.io's APIs (15)

- [2s.io: company hierarchy API pricing, 2 plans](https://datacircle.dev/company-hierarchy-apis/2s-io/free/llms.txt)
- [2s.io: domain WHOIS API pricing, 2 plans](https://datacircle.dev/domain-whois-apis/2s-io/free/llms.txt)
- [2s.io: email verification API pricing, 2 plans](https://datacircle.dev/validate-email-apis/2s-io/free/llms.txt)
- [2s.io: local business search API pricing, 2 plans](https://datacircle.dev/local-business-search-apis/2s-io/free/llms.txt)
- [2s.io: news API pricing, 2 plans](https://datacircle.dev/news-apis/2s-io/free/llms.txt)
- [2s.io: GitHub profile API pricing, 2 plans](https://datacircle.dev/github-profile-apis/2s-io/free/llms.txt)
- [2s.io: GitHub repository API pricing, 2 plans](https://datacircle.dev/github-repository-apis/2s-io/free/llms.txt)
- [2s.io: GitHub user repository API pricing, 2 plans](https://datacircle.dev/github-user-repository-apis/2s-io/free/llms.txt)
- [2s.io: Hacker News search API pricing, 2 plans](https://datacircle.dev/hacker-news-search-apis/2s-io/free/llms.txt)
- [2s.io: company enrichment API pricing, 2 plans, GET /api/business/br-cnpj](https://datacircle.dev/company-enrichment-apis/2s-io/free-trial-get-api-business-br-cnpj/llms.txt)
- [2s.io: company enrichment API pricing, 2 plans, GET /api/business/lei](https://datacircle.dev/company-enrichment-apis/2s-io/free-trial-get-api-business-lei/llms.txt)
- [2s.io: company enrichment API pricing, 2 plans, GET /api/business/pl-krs](https://datacircle.dev/company-enrichment-apis/2s-io/free-trial-get-api-business-pl-krs/llms.txt)
- [2s.io: company enrichment API pricing, 2 plans, GET /api/tax/vat](https://datacircle.dev/company-enrichment-apis/2s-io/free-trial-get-api-tax-vat/llms.txt)
- [2s.io: business verification API pricing, 2 plans, GET /api/business/entity-profile](https://datacircle.dev/business-verification-apis/2s-io/free-trial-get-api-business-entity-profile/llms.txt)
- [2s.io: business verification API pricing, 2 plans, GET /api/business/fi-companies](https://datacircle.dev/business-verification-apis/2s-io/free-trial-get-api-business-fi-companies/llms.txt)
- [2s.io: business verification API pricing, 2 plans, GET /api/business/fr-companies](https://datacircle.dev/business-verification-apis/2s-io/free-trial-get-api-business-fr-companies/llms.txt)
- [2s.io: business verification API pricing, 2 plans, GET /api/business/no-companies](https://datacircle.dev/business-verification-apis/2s-io/free-trial-get-api-business-no-companies/llms.txt)
- [2s.io: business verification API pricing, 2 plans, GET /api/business/sos-search](https://datacircle.dev/business-verification-apis/2s-io/free-trial-get-api-business-sos-search/llms.txt)
- [2s.io: business verification API pricing, 2 plans, GET /api/business/uk-companies](https://datacircle.dev/business-verification-apis/2s-io/free-trial-get-api-business-uk-companies/llms.txt)
- [2s.io: IP company lookup API pricing, 2 plans, GET /api/geo/ip](https://datacircle.dev/ip-company-lookup-apis/2s-io/free-trial-get-api-geo-ip/llms.txt)
- [2s.io: IP company lookup API pricing, 2 plans, POST /api/ipinfo/bulk](https://datacircle.dev/ip-company-lookup-apis/2s-io/free-trial-post-api-ipinfo-bulk/llms.txt)
- [2s.io: IP company lookup API pricing, 2 plans, GET /api/net/ip-resolve](https://datacircle.dev/ip-company-lookup-apis/2s-io/free-trial-get-api-net-ip-resolve/llms.txt)
- [2s.io: job postings API pricing, 2 plans, GET /api/gov/usajobs](https://datacircle.dev/job-posting-apis/2s-io/free-trial-get-api-gov-usajobs/llms.txt)
- [2s.io: job postings API pricing, 2 plans, GET /api/job/federal-search](https://datacircle.dev/job-posting-apis/2s-io/free-trial-get-api-job-federal-search/llms.txt)
- [2s.io: web search API pricing, 2 plans, GET /api/search/ai](https://datacircle.dev/web-search-apis/2s-io/free-trial-get-api-search-ai/llms.txt)
- [2s.io: web search API pricing, 2 plans, GET /api/search/web](https://datacircle.dev/web-search-apis/2s-io/free-trial-get-api-search-web/llms.txt)
- [2s.io: web scraping API pricing, 2 plans, POST /api/search/extract](https://datacircle.dev/web-scraping-apis/2s-io/free-trial-post-api-search-extract/llms.txt)
- [2s.io: web scraping API pricing, 2 plans, GET /api/url/clean](https://datacircle.dev/web-scraping-apis/2s-io/free-trial-get-api-url-clean/llms.txt)
- [2s.io: web scraping API pricing, 2 plans, GET /api/url/render](https://datacircle.dev/web-scraping-apis/2s-io/free-trial-get-api-url-render/llms.txt)

## 2s.io: domain WHOIS API alternatives

- [Companyfacts, $49 monthly](https://datacircle.dev/domain-whois-apis/companyfacts/49-monthly/llms.txt): $2.45 per 1,000, 67% complete
- [HackerTarget, $250 pack](https://datacircle.dev/domain-whois-apis/hackertarget/250-pack/llms.txt): $2.50 per 1,000, 89% complete, live
- [Vee3, $5 monthly, Starter, GET /v1/domains/lookup](https://datacircle.dev/domain-whois-apis/vee3/5-monthly-starter-get-v1-domains-lookup/llms.txt): $2.50 per 1,000, 78% complete
- [AI Rook, pay as you go](https://datacircle.dev/domain-whois-apis/ai-rook/pay-as-you-go/llms.txt): $2.50 per 1,000, 33% complete

## Sources

From each provider's own pricing page and docs, and from what providers tell us. We read this row from these pages on 2026-11-09.

- https://2s.io?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- https://2s.io/?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- https://2s.io/.well-known/x402?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- https://2s.io/catalog.txt?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- https://2s.io/domain/whois?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- https://2s.io/llms.txt?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- https://2s.io/openapi.json?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing