runsonwhat
New The runsonwhat Chrome extension is hereChrome extension New The runsonwhat API is liveAPI

Find every company thatruns on the tools you sell against, or sell alongside

Pick a tool and get the companies that use it. Each match comes with the public record that gave it away: a DNS entry, a subdomain, a script on their site.

1,503,201 companies scanned · 1,419 tools tracked · 16,725,609 matches

Every tool is a list of companies

Start with the ones everyone's asking about.

And the software that never touches a website, caught in DNS records, mail settings and internal subdomains.

Browse all 1,419 tools

What go-to-market teams do with it

For sales and founders

Prospect your competitor's customers

Pick the tool you replace. Every company running it already pays to solve the problem you solve, which makes for a short first email.

See plans

For marketing and RevOps

Find teams that bought into a category

Companies on Anthropic, Cursor or Vanta have already said yes to AI or compliance tooling. Build the segment that fits next to what you sell.

See plans

For account executives

Know their stack before the call

Look up a prospect's website and walk in knowing their CRM, their help desk and how they bill, with the record behind each one.

Works today: look up a site

For customer success and partnerships

Notice when a tool goes away

A verification record that disappears or a script that stops loading is often the first public sign of a switch. We rescan sites to catch it.

On the way

Every match comes with receipts

We don't guess from job posts or surveys. A company shows up under a tool only when a public record names it, and we show you that record so you can check it yourself.

  • Tools that never touch a website. When a team signs up for Anthropic, OpenAI, Atlassian or Slack, someone adds a verification record to the company's DNS. Website-only trackers never see it.
  • Five kinds of public record. DNS and mail settings, certificate logs and subdomains, website scripts, the tags inside Google Tag Manager, and the subprocessor lists privacy law requires.
  • More sources, more confidence. A tool seen in two independent places scores higher than one seen once.
acme.comAn example with a made-up company
  • DNS TXT record on acme.comanthropic-domain-verification=Xa91…Anthropic
  • Subdomain CNAMEhelp.acme.com → acme.zendesk.comZendesk
  • Script on the homepage<script src="https://widget.intercom.io/…">Intercom
tools we can detect
1,419
categories, from hosting to payroll
27
tools we can spot from a DNS verification record alone
338

Browse all 1,419 tools

Grouped by where they sit in the stack, from hosting to payroll. Pick one to see who runs on it.

Edge & Hosting

where the bytes are served from66 tools

Application

what the product is built with201 tools

Data & Observability

what they measure and store164 tools

Go-to-market

how they find and keep customers593 tools

Company Ops

what the team runs on day to day395 tools

Questions people ask

What is runsonwhat?

runsonwhat is a tech stack lookup built from public evidence. It answers two questions: which companies use a given tool, and which tools a given company uses. Pick any of the 1,400+ tools runsonwhat tracks to see its companies by industry, size and country, or open a company's page to see its stack. Every match shows the kind of public record it came from, such as a DNS entry, a certificate or a script on the website.

How does runsonwhat know what tools a company uses?

runsonwhat reads the public traces software leaves behind. Domain verification and email records in DNS name vendors like Google Workspace, HubSpot or Slack. Certificate logs reveal subdomains that point at tools like Zendesk or Okta. A website's scripts, tag manager and code show analytics, chat and ad tools, and a real-browser crawl of millions of homepages catches tags that load only at runtime. Published subprocessor lists name the rest.

How accurate is runsonwhat's data?

runsonwhat lists a company under a tool only when it has direct public evidence, or when several signals agree, and every match shows the kind of record behind it so you can check it yourself. Weak hints, like a vendor's name in a content security policy, don't count, and a company's own products are left out, so Stripe isn't listed as a Stripe customer. The methodology page explains exactly what counts as a match.

How often is runsonwhat updated?

runsonwhat rechecks every company's DNS records weekly and rescans websites about once a month, sooner when a scan comes back incomplete. The real-browser crawl is read monthly and public job boards weekly. A website lookup runs live, so you can check any domain right now, and the Chrome extension reads the page you're on as you open it.

Can I see when a company started or stopped using a tool?

Yes. runsonwhat records when a company starts, stops or comes back to a tool, and every tool page has "Using it now" and "Dropped it" tabs. A stop counts only when two checks by the same method disagree. Where a certificate proves when a company began using a tool, runsonwhat shows the date, and signed-in users can follow tools and get a weekly email of who started and stopped.

Can I export a list of companies that use a tool?

Yes. Signed-in runsonwhat users can export any tool's company list as a CSV, with the industry, size, country and LinkedIn filters they set, and the file arrives by email. Each row has the company name, domain, LinkedIn URL, industry, size, country, city, when it started using the tool and a link to its runsonwhat profile, ready for Clay, a CRM or a spreadsheet.

Does runsonwhat have an API?

Yes. The runsonwhat API returns any company's tech stack, the companies using a tool with industry, size and country filters, and who started or stopped a tool, as JSON, with the kind of evidence behind each match. Create a key on the API page of your runsonwhat account and read the reference at runsonwhat.com/docs. Calls use credits, charged only for the results returned.

Is there a runsonwhat Chrome extension?

Yes. The runsonwhat Chrome extension shows the tech stack of the site in your current tab: the tools its page loads, plus what runsonwhat found in the company's DNS, email and certificate records, with where each one was found. It sends only the site's domain to runsonwhat, never the page or your browsing, and can export the stack as a CSV. Get it at runsonwhat.com/extension.

How is runsonwhat different from BuiltWith or Wappalyzer?

runsonwhat reads far more than a website's code. Tools like BuiltWith and Wappalyzer mainly detect technologies from the pages a site loads; runsonwhat also reads DNS and email records, certificate logs and subprocessor lists, which reveal CRMs, help desks, identity providers and AI tools that never appear on a homepage. Every runsonwhat match shows the kind of evidence behind it, and tool pages track who starts and stops over time.

How do I remove my company from runsonwhat?

Email hello@runsonwhat.com with your domain and runsonwhat will stop scanning it and delete what it holds about it. To keep the crawler off your website, block runsonwhat-bot in your robots.txt; it identifies itself, obeys robots.txt and only follows links from your homepage. The crawler and data pages on runsonwhat.com explain what is collected and how removal works.

Learn more: how we detect tools · API docs · Chrome extension · our crawler and opt-out