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WhatRuns

See any website's tech stack instantly

Data & Discovery
For AI agents
None readiness
About

What is WhatRuns

WhatRuns is a browser extension that reads the tech stack of any website on demand — surfacing the CMS, frameworks, plugins, themes, fonts, analytics tools, and ad networks in use with a single click. It's built for founders and marketers at solo operations and small teams who need to understand what competitors or prospects are running without digging through source code. The standout capability is the ability to follow websites and receive updates when their technology stack changes, which turns a one-time lookup into an ongoing intelligence feed. Pricing is not publicly listed, so budget expectations are hard to set before signing up. It also has no API and no agentic readiness, so any workflow automation has to be done manually through the browser UI.

Data & Discovery
Capabilities

Key features

Tech-stack lookup

detects which tools a target company uses

Also ships

Chrome extension

Our verdict

Vanderbuild take

For founders and marketers who need fast, browser-level technology lookup on competitor or prospect sites, WhatRuns does the job without any setup overhead. That said, it's UI-only — there's no API and no MCP server, so you can't drive this from an agent or pipe results into a workflow without manual copy-paste. Pricing isn't publicly listed, which makes it hard to evaluate cost before you're already in the product. The follow-and-alert feature for tracking stack changes is genuinely useful for ongoing competitive monitoring, but the lack of any export or integration path means the data stays trapped in the extension.

Mateusz Sekta
Founder, vanderbuild
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Our Resources

The wedge

Agentic stack profile

API
Not public

No public programmatic access.

No public API. Not usable from an agent without scraping.

Agentic readiness
None

Not usable from an agent without scraping.

No public API. UI-only. Not usable from an agent without scraping, which we don't recommend.

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

WhatRuns alternatives

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

WhatRuns(this tool)
Best for
Founder, Marketing
Readiness
None
API
No
Larger
Best for
GTM Engineer
Readiness
Native
MCP
Yes
API
REST
Builtwith
Pricing
Freemium
Budget
$$$
Best for
SDR / BDR, RevOps
Readiness
Native
MCP
Yes
API
REST
Answers

Frequently asked questions

Does WhatRuns have a public API?

No — there's no publicly documented API as of today. WhatRuns is operated through its UI.

Who is WhatRuns best for?

WhatRuns is built for Founder, Marketing. Fits Solo, SMB (1-50)-sized teams.