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WhatCMS

See what's powering any website

Data & Discovery
For AI agents
APICapable readiness
About

What is WhatCMS

WhatCMS.org scans a website's content and returns a structured read of the CMS, hosting provider, WordPress theme, and broader technology stack powering it. GTM engineers use it to enrich prospect lists with firmographic-level tech data, while security researchers use it to map attack surfaces or audit third-party dependencies. The standout capability is its API, which gives programmatic access to all three detection services — CMS detection, hosting identification, and technology reports — under a single subscription. Coverage spans 1,200+ CMS and web technologies, including e-commerce platforms, web frameworks, and infrastructure layers like Cloudflare and Nginx. Where it falls short is depth: it tells you what technology a site runs, but not version details, configuration specifics, or any behavioral signals about how that technology is being used.

Data & Discovery
Capabilities

Key features

Tech-stack lookup

detects which tools a target company uses

Our verdict

Vanderbuild take

For GTM engineers building target-account lists by tech stack, or security researchers doing surface-area mapping, WhatCMS is a focused, no-frills lookup tool that does one thing without much ceremony. The REST API is solid — you can wrap it into your own enrichment pipeline or MCP layer cleanly, and the single-subscription model covering all three detection services keeps the integration surface small. Pricing starts at $20/mo for 10K detections, which sounds accessible, but at scale-up or enterprise volumes you'll be budgeting meaningfully, and the 1-per-10-second rate limit on all tiers will be a real constraint if you're trying to run bulk enrichment jobs fast. The honest ceiling here is that WhatCMS tells you *what* a site runs, not *how* it's configured or whether that tech is actively maintained — for deeper intelligence you'll need to layer in additional sources.

Mateusz Sekta
Founder, vanderbuild
Learn more

Our Resources

The wedge

Agentic stack profile

API
REST

Programmatic access available.

REST API — straightforward to call from any agent or workflow tool. Rate limits and auth vary by plan.

API docs →
Agentic readiness
Capable

Solid API access — wraps cleanly for agent use.

Solid REST or SDK access. No MCP server yet, but easy to wrap in custom agent tooling. Most modern SaaS tools land here.

Stack role
Enricher

Where this tool slots into an agentic pipeline.

Plays the role of Enricher in an agentic pipeline. Use it to add firmographic, technographic, and signal data to a lead row on the fly.

Compare

WhatCMS alternatives

Tools that solve a similar problem — compared at a glance.

WhatCMS(this tool)
Pricing
Freemium
Budget
$$$
Best for
GTM Engineer
Readiness
Capable
API
REST
Builtwith
Pricing
Freemium
Budget
$$$
Best for
SDR / BDR, RevOps
Readiness
Native
MCP
Yes
API
REST
NerdyData
Pricing
Freemium
Budget
$$$
Best for
SDR / BDR, Marketing
Readiness
Native
MCP
Yes
API
REST
Answers

Frequently asked questions

Does WhatCMS have a public API?

Yes — WhatCMS ships a REST API. Docs: https://api.whatcms.org/Documentation.

How much does WhatCMS cost?

WhatCMS: pricing is freemium, expect higher tier ($$$) spend. Full pricing page: https://whatcms.org/Subscriptions.

Who is WhatCMS best for?

WhatCMS is built for GTM Engineer. Fits Mid-market (50-500), Enterprise-sized teams.

How well does WhatCMS fit an agentic sales stack?

Tier: Capable. Solid public API, no MCP yet — straightforward to wrap in your own agent tooling.