# Arch Tools, free, POST /v1/tools/domain-check: Domain WHOIS API

> Check if a domain is registered or available via RDAP. Returns registration date, nameservers, expiry.

Arch Tools' Free plan for the domain WHOIS API costs $0.00 per 1,000 domains. We check each provider's docs for 9 fields. Arch Tools' docs list 3: Created on, Expires on, Name servers.
We haven't run Arch Tools through [our domain WHOIS API benchmark](https://datacircle.dev/best-domain-whois-api.txt) yet.
This plan is free. We rank 631 plans for domain WHOIS APIs by price. Half the plans cost $1.663 or less per 1,000 domains. [128 domain WHOIS API plans on our price sheet are free.](https://datacircle.dev/best-domain-whois-api.txt) [WhoisRequest's free plan](https://datacircle.dev/domain-whois-apis/whoisrequest/free-get-api-v1-lookup-whois-domain-name/llms.txt) scores highest of the free plans in our benchmark, at 96.9 out of 100.
[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. [UAPI's CNY 4.90 pack](https://datacircle.dev/domain-whois-apis/uapi/cny-4-90-pack/llms.txt) costs the least for 10,000 domains a month: about $0.73.
[WhoisRequest](https://datacircle.dev/domain-whois-apis/whoisrequest/free-get-api-v1-lookup-whois-domain-name/llms.txt), [thenetworkery](https://datacircle.dev/domain-whois-apis/thenetworkery/free/llms.txt) and [FluentEDI](https://datacircle.dev/domain-whois-apis/fluentedi/free/llms.txt) are the best domain WHOIS API providers in the Datacircle benchmark.

- This page: https://datacircle.dev/domain-whois-apis/arch-tools/free-post-v1-tools-domain-check
- [Domain WHOIS API in 2026: the best of 40+ providers compared](https://datacircle.dev/best-domain-whois-api.txt)
- Get it: https://archtools.dev/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- Request: `POST https://archtools.dev/v1/tools/domain-check`
- API key: with the plan, on https://archtools.dev/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- Its API docs: https://archtools.dev/docs?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing#domain-check
- Sold by: Arch Tools (https://archtools.dev?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing)
- Checked: 2026-11-10

## In the answer

- Completeness: 33%
- Created on: ✓
- Expires on: ✓
- Name servers: ✓

## Price

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

## Charges

- Also pays for: from the same budget: 62 other Arch Tools calls

## Not found

- $ per 1,000 calls that find nothing: $0.00

## In their words

- Their pitch: Check if a domain is registered or available via RDAP. Returns registration date, nameservers, expiry.

## Data

- Keep data: no limit
- Use data: Your use of the Service is governed by our full Acceptable Use Policy, which is incorporated into these Terms. In summary, you agree not to: Use the Service for any unlawful purpose, or violate any third-party rights or applicable laws [...] Reverse engineer, scrape, copy, resell, or sublicense the Service, or resell, transfer, or redistribute your API key or credits [...] Attempt to exceed rate limits, bypass authentication or billing, or abuse the platform [...] Use the Service to generate spam, malware, phishing, or harmful content

## Plan

- Pay: $0
- You get: 100 credits
- Enough for: 50 calls

## Rate limit

- Per day: 500
- Per second: 0.17 (600 an hour)
- Concurrent: 5
- Batch: 1

## Speed

- Answer: in the call

## The call

- You send: domain
- Method: POST
- Path: /v1/tools/domain-check

## About the plan

- Plan: Free
- Who can get it: anyone aged 18 or over with a valid email address

## The 5 fields the plan's answer can hold

domain, available, creation date, expiration date, name servers

## Arch Tools' plans (9)

- [Arch Tools, free, POST /v1/tools/domain-check](https://datacircle.dev/domain-whois-apis/arch-tools/free-post-v1-tools-domain-check/llms.txt): $0.00 per 1,000, 33% complete
- [Arch Tools, $9 pack, Starter Pack, POST /v1/tools/domain-check](https://datacircle.dev/domain-whois-apis/arch-tools/9-pack-starter-pack-post-v1-tools-domain-check/llms.txt): $6.00 per 1,000, 33% complete
- [Arch Tools, $49 pack, Pro Pack, POST /v1/tools/domain-check](https://datacircle.dev/domain-whois-apis/arch-tools/49-pack-pro-pack-post-v1-tools-domain-check/llms.txt): $3.92 per 1,000, 33% complete
- [Arch Tools, $199 pack, Business Pack, POST /v1/tools/domain-check](https://datacircle.dev/domain-whois-apis/arch-tools/199-pack-business-pack-post-v1-tools-domain-check/llms.txt): $3.184 per 1,000, 33% complete
- [Arch Tools, $19 monthly, Starter, POST /v1/tools/domain-check](https://datacircle.dev/domain-whois-apis/arch-tools/19-monthly-starter-post-v1-tools-domain-check/llms.txt): $3.80 per 1,000, 33% complete
- [Arch Tools, $49 monthly, Pro, POST /v1/tools/domain-check](https://datacircle.dev/domain-whois-apis/arch-tools/49-monthly-pro-post-v1-tools-domain-check/llms.txt): $3.267 per 1,000, 33% complete
- [Arch Tools, $99 monthly, Growth, POST /v1/tools/domain-check](https://datacircle.dev/domain-whois-apis/arch-tools/99-monthly-growth-post-v1-tools-domain-check/llms.txt): $2.64 per 1,000, 33% complete
- [Arch Tools, $199 monthly, Business, POST /v1/tools/domain-check](https://datacircle.dev/domain-whois-apis/arch-tools/199-monthly-business-post-v1-tools-domain-check/llms.txt): $2.274 per 1,000, 33% complete
- [Arch Tools, contact us, Enterprise, POST /v1/tools/domain-check](https://datacircle.dev/domain-whois-apis/arch-tools/contact-us-enterprise-post-v1-tools-domain-check/llms.txt): 33% complete

## Arch Tools' calls for this API (2)

- `POST /v1/tools/domain-check`: [Arch Tools, free, POST /v1/tools/domain-check](https://datacircle.dev/domain-whois-apis/arch-tools/free-post-v1-tools-domain-check/llms.txt)
- `POST /v1/tools/whois-lookup`: [Arch Tools, free, POST /v1/tools/whois-lookup](https://datacircle.dev/domain-whois-apis/arch-tools/free-post-v1-tools-whois-lookup/llms.txt)

## Arch Tools' APIs (9)

- [Arch Tools Email verification API pricing, 9 plans](https://datacircle.dev/validate-email-apis/arch-tools/free/llms.txt)
- [Arch Tools Email finder API pricing, 9 plans](https://datacircle.dev/find-email-apis/arch-tools/free/llms.txt)
- [Arch Tools IP company lookup API pricing, 9 plans](https://datacircle.dev/ip-company-lookup-apis/arch-tools/free/llms.txt)
- [Arch Tools News API pricing, 9 plans](https://datacircle.dev/news-apis/arch-tools/free/llms.txt)
- [Arch Tools Phone validation API pricing, 9 plans](https://datacircle.dev/validate-phone-apis/arch-tools/free/llms.txt)
- [Arch Tools Web search API pricing, 9 plans, POST /v1/tools/web-search](https://datacircle.dev/web-search-apis/arch-tools/free-post-v1-tools-web-search/llms.txt)
- [Arch Tools Web search API pricing, 9 plans, POST /v1/tools/semantic-search](https://datacircle.dev/web-search-apis/arch-tools/free-post-v1-tools-semantic-search/llms.txt)
- [Arch Tools SERP API pricing, 9 plans](https://datacircle.dev/serp-apis/arch-tools/free/llms.txt)
- [Arch Tools Domain WHOIS API pricing, 9 plans, POST /v1/tools/domain-check](https://datacircle.dev/domain-whois-apis/arch-tools/free-post-v1-tools-domain-check/llms.txt)
- [Arch Tools Web scraping API pricing, 9 plans, POST /v1/tools/extract-metadata](https://datacircle.dev/web-scraping-apis/arch-tools/free-post-v1-tools-extract-metadata/llms.txt)
- [Arch Tools Web scraping API pricing, 9 plans, POST /v1/tools/extract-page](https://datacircle.dev/web-scraping-apis/arch-tools/free-post-v1-tools-extract-page/llms.txt)
- [Arch Tools Web scraping API pricing, 9 plans, POST /v1/tools/web-scrape](https://datacircle.dev/web-scraping-apis/arch-tools/free-post-v1-tools-web-scrape/llms.txt)

## Arch Tools: domain WHOIS API alternatives

[Arch Tools alternatives: other domain WHOIS API providers by price](https://datacircle.dev/arch-tools-alternatives.txt)

We list Arch Tools' cheapest paid plan first. Next we list other providers' plans closest to Arch Tools in price per 1,000 domains.

- [Arch Tools, $199 monthly, Business, POST /v1/tools/domain-check](https://datacircle.dev/domain-whois-apis/arch-tools/199-monthly-business-post-v1-tools-domain-check/llms.txt): $2.274 per 1,000, 33% complete
- [Wapi, CNY 150 pack](https://datacircle.dev/domain-whois-apis/wapi/cny-150-pack/llms.txt): $2.243 per 1,000, 78% complete
- [Shunwei, top-up](https://datacircle.dev/domain-whois-apis/shunwei/top-up/llms.txt): $2.243 per 1,000, 56% complete
- [TrustLookup, $79 monthly](https://datacircle.dev/domain-whois-apis/trustlookup/79-monthly/llms.txt): $2.257 per 1,000, 33% complete, 24 hours
- [JsonWhois, $21.49 monthly](https://datacircle.dev/domain-whois-apis/jsonwhois/21-49-monthly/llms.txt): $2.262 per 1,000, 78% complete, 1 week

## Sources

From each provider's own pricing page and docs, and from what providers tell us. We read this row from these pages on 2026-11-10.

- https://archtools.dev?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- https://archtools.dev/docs?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- https://archtools.dev/faq?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- https://archtools.dev/legal/terms?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- https://archtools.dev/openapi.json?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing
- https://archtools.dev/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=domain-whois-api-pricing