SaaS Customer Finder: Companies Using Any Tool

Name a tool, get the companies that use it, with contacts. Atlassian, OpenAI, Anthropic, Slack, Zoom, DocuSign, Salesforce, HubSpot, Microsoft 365, Google Workspace, Shopify, Klaviyo, Stripe, Intercom, Zendesk and 170 technologies in all.

Most tech lookup tools only read the homepage, so they see the website's widgets and nothing behind them. This actor also reads the company's public DNS records. To switch on Atlassian, DocuSign, ChatGPT Enterprise, Slack or Zoom for a company domain, the vendor makes the company publish a verification record, and every email sender has to be listed in SPF. Those records show the internal stack: tools that never appear on a website.

No login, no API key, no browser, no proxy.

What you get

One row per company that uses the tool:

Field	Example
domain	loyaltylion.com
companyName	LoyaltyLion
matchedTechnologies	["Atlassian"]
primaryEmail	hello@loyaltylion.com
emails, phones	every public address and tel: number on the site
linkedin, social	LinkedIn company page, X, Facebook, Instagram, YouTube, GitHub
emailProvider	Google Workspace, Microsoft 365, Zoho Mail...
technologies	the full detected stack, each with where it was seen (dns or homepage) and the exact evidence
byCategory	the stack grouped: collaboration, ai, security, marketing, support, hosting, cms, ecommerce...
rank	the company's position in the Tranco top sites list
leadTier	lead (has its own email) or match

Each detection carries its evidence (for example txt: atlassian-domain-verification=... or html: static.klaviyo.com), so you can check any row yourself.

Examples

• Sell a Jira add-on: technologies: ["Atlassian"], startRank: 20000
• Pitch AI governance tools to companies already paying for ChatGPT Enterprise or Claude: ["OpenAI", "Anthropic"]
• Shopify stores on Klaviyo (both required): ["Shopify", "Klaviyo"], matchMode: "all"
• German companies on Microsoft 365: ["Microsoft 365"], tlds: ["de"]
• Enrich your own list: put a CRM export in domains and ask for ["Salesforce", "HubSpot"]

Where the companies come from

By default it walks the Tranco list, a research-grade ranking of the top 1 million sites, refreshed daily. The first few thousand ranks are global giants, so start at startRank: 5000 or deeper for mid-size companies you can actually reach. When a run ends, the SUMMARY record gives nextStartRank so the next run continues where this one stopped.

Or pass your own domains list and it checks only those.

Speed

• DNS-detectable tools (Atlassian, OpenAI, Anthropic, Slack, Zoom, DocuSign, Microsoft 365, Google Workspace, Salesforce, Stripe, SendGrid...): about 10 domains a second. The homepage is fetched only for matches.
• Homepage-only tools (Shopify, Klaviyo, WordPress, Webflow, Intercom widget...): about 2 to 3 domains a second, because every candidate's homepage is read.

Pricing

Pay per company found. Scanning is free.

Event	Price	When
company_match	$0.01	the company uses the tool, no email of its own found
company_lead	$0.03	the company uses the tool, and a public email on its own domain was found

The first matched company in every run is free. A run that finds nothing costs nothing but compute, and returns a note explaining why.

Notes

• Only public data is read: DNS records every resolver answers, and pages any visitor can open. Nothing behind a login.
• Homepage checks are one direct request from Apify's servers, with no proxy. A few sites stall or block that traffic, so homepage-only tools (Shopify, Klaviyo, WordPress...) can miss them. DNS detections are not affected.
• A company that has not published a verification record will not be found through DNS even if it uses the tool, so treat results as "confirmed users", not "all users".
• An unrecognised tool name returns the full supported list in a free note row.