WhoisJSON API
What WhoisJSON API is
WhoisJSON API provides REST endpoints for internet and domain lookups. It covers WHOIS records, DNS, SSL certificates, domain availability, email-domain intelligence, subdomain discovery and monitoring. The service says it supports more than 1,500 generic and country-code top-level domains, using RDAP where available. Responses are returned as JSON by default, with XML available through the format=xml parameter. Results remain cached for three hours; adding _forceRefresh=1 bypasses that cache for two credits on most plans. Official clients are listed for PHP, Python 3.7+ and Node.js, while an MCP server is described for Claude, Cursor and Windsurf. Plans include a free Basic option with 1,000 requests monthly, 20 requests per minute and one monitored domain; paid plans start at $10 a month. Commercial use is allowed on every plan, including Basic. Monthly quotas produce HTTP 429 responses after exhaustion.
Who it suits
WhoisJSON suits developers, cybersecurity professionals, businesses, brand-protection teams, domain portfolio managers and DevOps users needing programmatic lookup data. Its client libraries, MCP server and commercial-use terms also fit applications and internal tools.
What it does well
- Covers WHOIS, DNS, SSL and domain availability lookups
- Supports more than 1,500 generic and country-code TLDs
- Free Basic plan includes 1,000 requests monthly
- Official PHP, Python and Node.js clients listed
- Commercial use allowed on all plans
What to know first
- No free trial is offered
- Responses are cached for three hours
- Quota exhaustion returns HTTP 429 until renewal
- Force-refresh costs two credits on most plans
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Basic | 1,000 requests/month · 20 req/min · 1 monitored domain · JSON | Free |
| Pro | Monthly; yearly billing costs 10 months for 12 months of access · 30,000 requests/month · 40 req/min · 5 monitored domains · JSON | $10 a month |
| Giga | Monthly; yearly billing costs 10 months for 12 months of access · Unlimited requests · 200 req/min · 100 monitored domains | $120 a month |
| Tera | Monthly; yearly billing costs 10 months for 12 months of access · Unlimited requests · 300 req/min · 150 monitored domains | $200 a month |
| Ultra | Monthly; yearly billing costs 10 months for 12 months of access · 150,000 requests/month · 60 req/min · 20 monitored domains · JSON | $30 a month |
| Titan | Monthly; yearly billing costs 10 months for 12 months of access · Unlimited requests · 600 req/min · 500 monitored domains | $399 a month |
| Scale | Monthly; yearly billing costs 10 months for 12 months of access · 1,000,000 requests/month · 100 req/min · 30 monitored domains · JSON | $50 a month |
| Atlas | Monthly; yearly billing costs 10 months for 12 months of access · Unlimited requests · 900 req/min · 500 monitored domains | $600 a month |
The first 8 of 9 plans, as whoisjson.com lists them, read 7 Oct 2026. The maker's own page has the final word. Every plan
Verdict
WhoisJSON API combines broad domain intelligence coverage with documented clients and a free starting plan. Check request limits and cache behavior when your application needs frequent fresh results.
Facts from WhoisJSON API's own pages
- API documentation
- Yes · whoisjson.com, 20 Sept 2026
- Caching
- Responses are cached for a three-hour TTL, and _forceRefresh=1 bypasses the cache at a cost of two credits on most plans. · whoisjson.com, 7 Oct 2026
- Commercial use
- The pricing page says all plans, including Basic, allow commercial use in SaaS products, internal tools, client dashboards, and business applications. · whoisjson.com, 7 Oct 2026
- Coverage
- The service says it supports more than 1,500 generic and country-code TLDs and uses RDAP where supported. · whoisjson.com, 7 Oct 2026
- Free plan
- Yes · whoisjson.com, 20 Sept 2026
- Integrations
- Official clients are listed for PHP, Python 3.7+, and Node.js, and the MCP server is described as compatible with Claude, Cursor, and Windsurf. · whoisjson.com, 7 Oct 2026
- Intended users
- The maker describes use cases for developers, cybersecurity professionals, businesses, brand protection, domain portfolio management, and DevOps. · whoisjson.com, 7 Oct 2026
- Privacy
- The terms state that WhoisJSON does not sell, rent, or share personal information with third parties for marketing purposes. · whoisjson.com, 7 Oct 2026
- Product
- WhoisJSON provides a REST API for WHOIS, DNS, SSL certificate, domain availability, email domain intelligence, subdomain discovery, and monitoring lookups. · whoisjson.com, 7 Oct 2026
- Quota behavior
- After the monthly request quota is reached, further API calls return HTTP 429 until the next billing cycle. · whoisjson.com, 7 Oct 2026
- Response formats
- API endpoints return JSON by default and can return XML with the format=xml parameter. · whoisjson.com, 7 Oct 2026
- Security
- The pricing page states that all traffic is encrypted end-to-end and the service is HTTPS-only. · whoisjson.com, 7 Oct 2026
- Support
- The API documentation says the support team typically responds within a few hours. · whoisjson.com, 7 Oct 2026
Where WhoisJSON API stands on Freedom251
- API clients#29 of 38