Updated March 2026 · 7 min read

WhoisXML API vs JsonWhois: WHOIS API Comparison for Developers in 2026

Choosing a WHOIS API often comes down to WhoisXML API (the enterprise incumbent) versus JsonWhois (the budget-friendly alternative). Both return domain registration data, but they serve very different audiences. We'll compare them head-to-head and introduce a third option that bridges the gap.

Feature	WhoisXML API	JsonWhois	Strongwell WHOIS
Free Tier	500 queries	500/month	Free tier included
RDAP Support	✅ Full	Partial	✅ Full
Reverse WHOIS	✅	❌	❌
Historical Data	✅ Extensive	❌	❌
Response Format	JSON/XML	JSON	JSON
Paid Plans From	~$99/mo	$9/mo	Pay-per-query
SDKs	Multiple	None	REST (any language)
DNS Records	✅ (separate product)	❌	✅ Included

WhoisXML API: The Enterprise Powerhouse

WhoisXML API is the most feature-rich WHOIS data provider on the market. Beyond basic WHOIS lookups, they offer domain reputation scoring, website categorization, DNS lookup, IP geolocation, and over 50 other data products. Their historical WHOIS database contains billions of records spanning over a decade.

This depth comes at a cost. Plans start at approximately $99/month (as of 2026), and many advanced features — historical WHOIS, bulk lookups, reverse WHOIS — require higher tiers. The API surface is large, with different endpoints and authentication methods across products. For a developer who just needs to look up who registered a domain, there's a lot of overhead.

WhoisXML API Strengths

• Deepest WHOIS database available (historical records back 10+ years)
• Reverse WHOIS for finding domains by registrant
• Enterprise SLAs and support
• Comprehensive SDKs and documentation

WhoisXML API Weaknesses

• Enterprise pricing — overkill for small teams
• Complex product suite with many separate endpoints
• Free tier is one-time credits, not recurring monthly

JsonWhois: The Budget Alternative

JsonWhois strips WHOIS lookups to the essentials: send a domain, get back JSON with registration data. The API is simple, well-documented, and affordable. At $9/month for their starter plan, it's roughly 10x cheaper than WhoisXML API.

The trade-off is feature depth. JsonWhois doesn't offer historical data, reverse WHOIS, or DNS records. RDAP support is limited to certain TLDs. If your use case is straightforward domain verification or registration monitoring, these limitations may not matter. If you need investigative capabilities, they will.

JsonWhois Strengths

• Simple, clean JSON responses
• Affordable at $9/month
• 500/month free tier for testing
• Straightforward API — one endpoint, one purpose

JsonWhois Weaknesses

• No historical WHOIS data
• No reverse WHOIS capability
• Limited RDAP support
• No official SDKs

Strongwell WHOIS Domain Intel API: The Developer-First Middle Ground

Strongwell's WHOIS Domain Intel API sits between WhoisXML API's enterprise complexity and JsonWhois's minimalism. It provides clean, structured domain intelligence — registrar data, dates, nameservers, DNSSEC status, and available contact information — with full RDAP support and DNS records included in the same API.

The key differentiator is the pricing model. Instead of monthly subscriptions, Strongwell uses pay-per-query pricing. You pay for what you use, with a free tier included for development and low-volume production use. This makes it particularly attractive for applications with variable or growing query volumes.

The API automatically handles the WHOIS-to-RDAP transition, querying the best data source for each TLD without requiring you to manage protocol differences. Response times are consistently fast thanks to Cloudflare edge deployment.

Strongwell WHOIS Strengths

• WHOIS + RDAP dual protocol (automatic selection)
• DNS records included — no separate API needed
• Pay-per-query pricing — no monthly commitment
• Edge-deployed for global low latency
• Free tier for development and low-volume use

Which Should You Choose?

The right choice depends on your specific needs:

• Enterprise security or brand protection team → WhoisXML API. You need historical data, reverse WHOIS, and enterprise SLAs. The price is justified by the depth.
• Hobby project or simple domain verification → JsonWhois. At $9/month, it does basic lookups reliably and affordably.
• Developer building a product with domain data → Strongwell WHOIS Domain Intel. Pay-per-query scaling, modern protocol support, and no subscription overhead make it the pragmatic choice for most development teams.