WhatRuns
See any website's tech stack instantly
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.
Key features
detects which tools a target company uses
Chrome extension
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.
Agentic stack profile
APINot publicNo public programmatic access.
No public API. Not usable from an agent without scraping.
Agentic readinessNoneNot usable from an agent without scraping.
No public API. UI-only. Not usable from an agent without scraping, which we don't recommend.
Stack roleEnricherWhere 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.
WhatRuns alternatives
Tools that solve a similar problem — compared at a glance.
- Best for
- Founder, Marketing
- Readiness
- None
- API
- No
- Best for
- GTM Engineer
- Readiness
- Native
- MCP
- Yes
- API
- REST
- Pricing
- Freemium
- Budget
- $$$
- Best for
- SDR / BDR, RevOps
- Readiness
- Native
- MCP
- Yes
- API
- REST
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.