Companies using Knock

1 companies in the VendorStacks index name Knock as part of their email stack in their public web presence. Every match carries the quoted source row it was extracted from — no inference, no fingerprint guessing.

Sample of companies using Knock

Commonly appears alongside

Vendors that most often show up in the same stacks as Knock.

How this is collected

VendorStacks runs a multi-source extraction pipeline over a company's public web presence: crawling, rendering JavaScript pages and PDFs, and matching a deterministic vendor taxonomy against what the company itself publishes. Nothing is inferred from tracking pixels or guessed from job posts — if we say a company uses Knock, we can show you the sentence that says so. How it works →

Most recent refresh in this set: 2026-08-01.