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Authentication Services tools, and the websites running each one.

Hunter tracks 19 Authentication Services technologies. Each one has a page listing the websites it was detected on and the email addresses Hunter holds for them.

Most-used Authentication Services tools

Ranked by the number of websites in Hunter's index where each tool was detected.

  1. 1 reCAPTCHA 292,967 websites
  2. 2 Gravatar 19,026 websites
  3. 3 OpenSSL 18,084 websites
  4. 4 Google Sign-in 8,823 websites
  5. 5 DocuSign 2,094 websites
  6. 6 FingerprintJS 1,560 websites
  7. 7 CIVIC 1,051 websites
  8. 8 Ace 336 websites
  9. 9 Auth0 322 websites
  10. 10 Plaid 177 websites

All Authentication Services technologies

Every Authentication Services technology with a page on Hunter, A to Z.

Knowing who uses reCAPTCHA is step one.

The websites are the easy half. Hunter turns each of those domains into named people with verified email addresses, so a detected tool becomes a list you can write to.

Sign up to reveal the companies

Finding companies by their Authentication Services stack

The count beside each tool is the number of ranked websites in Hunter's index where that tool was detected. It is a floor, not a vendor's customer list.

A detection describes what a site runs today, and a tag left in place after a team stopped paying still counts — so treat one detection as a lead to check. Two tools from this page on the same domain is the more interesting signal: a migration, a trial, or an old tag nobody removed. All three mean the decision is open.

Every technology page here lists the ranked websites running that tool. Discover takes the same signal as a filter and adds company size, industry and country on top, so the list narrows to the accounts you actually sell to.

Authentication Services technology FAQs

Hunter keeps an index of websites and records the technologies detected on each one. Every page in this section is built from that index and rebuilt daily.

Once a day. A page whose numbers did not move keeps its previous date, so the sitemap does not claim a change that did not happen.

Yes. Open the tool's page to see the websites it was detected on, then use Discover to filter the same signal by company size, industry and country before you export the contacts.

A technology earns a page once Hunter has detected it on enough websites for the page to say something useful. Tools below that line are still detected and still searchable — they just get no page of their own.
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