Developer tools decision
Whois JSON API
A capable developer can build a usable single/bulk WHOIS+DNS API with caching and auth in about a week, but reproducing the vendor's scale, tiered global caching, accuracy guarantees, and managed SLA is operationally heavy and costly.
Visit website↗$49/mo
$588/yr
Read off the official pricing page.
$100one-off40 h to build
$50/mo6 h/mo upkeep
On cash alone, building overtakes the subscription at 2 seats.
Open-source builds that already do this
Every project below is open source and already does this job today. Fork one, self-host it, or take the parts you need - the build prompt further down assumes an empty file, and this is the shortcut past that. Licences differ; check the one on each card before you ship. All Whois JSON API alternatives, with the arithmetic →
What a replacement has to do
- Accept authenticated REST requests for single or bulk domain lookups; query RDAP/WHOIS registries and DNS resolvers; normalize and cache results; return structured JSON and quota headers.
What it still won’t have
- Their described "sophisticated tiered caching system to ensure sub-millisecond response times"
- Operational scale and SLA-grade reliability/priority support for higher tiers
- Multi-million domain indexing and any proprietary smoothing/normalization optimizations claimed ("99.9%" accuracy)
- Turnkey hosted quota management and credit-based billing
What remains hard
- Infrastructure at scale
We query source registries and maintain a sophisticated tiered caching system to ensure sub-millisecond response times.
- Brand trust
Providing developers with reliable WHOIS data since 2018.
First-year cost
Keep paying
Paying is—cheaper in year one.
On cash alone, building overtakes the subscription at 2 seats.
Money you would actually spend
Time you would spend
—
What you would spend
What we assumed
The verdict above measures whether you could build it. This one is only about money.
Runnable build prompt
Build a self-hosted domain intelligence REST service (Go + Gin for API, Redis for cache, Postgres for minimal metadata, golang-rdap + system whois calls + miekg/dns resolver). Implement: bearer-token auth and simple key dashboard; GET /v1/{domain} WHOIS/RDAP lookup with normalized JSON; GET /v1/domains?d=... bulk (max 20) with parallel fetches; GET /v1/dns/{domain}?types=... using DNS resolver library; caching layer with 24h TTL and headers X-Requests-Remaining; rate limiter (50 rps global) and request-credit accounting stored in Postgres; robust error handling, retries, timeouts, and unit + integration tests. Out of scope: distributed multi-region cache, paid billing portal, enterprise SLA/priority support. Provide Docker Compose for local dev and a production deploy script for one DigitalOcean droplet + managed Redis.How we checked
How the score was reached
- Partly verdict base52
- An open-source build was found+5
- 4 cited sources+3
- Price verified on pricing page+3
- Hard moats found in the evidence-3
- Evidence score60
The base comes from the verdict. Everything under it is a check that either happened or did not, and each one is a fact frozen in this record rather than a judgement made at render time - so the same evidence always produces the same number.
How scoring works →Cited sources · 4
Every page the run actually retrieved.
- official productWhoisJSONAPI home
- official pricingWhoisJSONAPI Pricing
- official docsWhoisJSONAPI Documentation
- open sourcepirxthepilot/wtfis
Integrity checks
What held up, and what did not.
