Companies Using Clerk

We detect Clerk on 8,315 domains, including Engel & Völkers, Coderhouse, Fusion Medical Staffing, LLC. A detection means the technology is present on that domain, which for large organisations is often a single storefront or subdomain rather than a company-wide deployment. Among domains we matched to a company with a resolved industry, the most common is Software Development (16.15%).

We detect 8,315 domains running Clerk across our monthly crawl of live business domains. Company data could be matched for 5,555 of them (66.8%), and every company-size, industry and country breakdown on this page describes that matched subset rather than the full detected base. A further 1,012 domains carried a Clerk detection previously and no longer do.

Clerk holds 0.85% of the Identity & Access (SSO/CIAM) category, ranking #8. This is a share of the domains we detect running a platform in this category — not a share of all websites, and not a share of spending — so it is not directly comparable to figures published on other denominators.

The top alternatives to Clerk include Facebook Login (63.43% market share), Google Sign-in (22.36% market share), Duo Security (2.15% market share), Linkedin Sign-in (2.15% market share) — measured as a share of the domains we detect running a platform in this category.

United States leads with 2,093 matched Clerk domains, followed by United Kingdom (389), India (250), Canada (204), Australia (198). These are counts within the 5,555 domains we could match to a company record, not the full detected base.

The most common company size is 1-10 employees, representing 76.25% of the Clerk domains we could match to a company record and size — a subset of 5,555 matched companies, not of all 8,315 detected domains. This is followed by 11-50 employees (17.71%) and 51-200 employees (4.04%).

Among the Clerk domains we could match to a company with a known founding date, the largest group was founded in the 2020s (63.18%), followed by the 2010s (27.1%). That matched subset is drawn from 5,555 companies and is not representative of all 8,315 detected domains. This suggests Clerk is most popular among relatively young companies.

The ideal Clerk customer is: Company Size: 1-10 employees, Location: Denmark, Italy, or UK, City: Copenhagen, Milan, Rome, London, Founded: 2010-2019, Company Age: ~10-15 years old — based on our analysis of 5,555 enriched companies at TechnologyChecker.io.

Clerk is SOC 2 Type II certified and implements security measures including brute force protection, CSRF protection, and bot detection. It supports multi-factor authentication, passkeys, and session management with configurable lifetimes. Clerk is certified under the Data Privacy Framework for GDPR-compliant usage, based on their published security documentation.

Clerk offers a free Hobby plan with up to 50,000 monthly retained users per application, unlimited applications, and 3 dashboard seats. The free tier includes core auth features, custom domains, and most authentication methods. You don't need a credit card to start. Paid Pro plans begin at $20 per month for additional features and higher limits.

Clerk Pro starts at $20 per month and charges per monthly retained user beyond the free tier. A 'monthly retained user' is someone who visits your app at least one day after signing up, so trial users who never return aren't billed. Annual billing offers discounts. Enterprise plans with migration assistance and custom pricing are available through their sales team.

Clerk provides pre-built, customizable UI components for sign-up, sign-in, user profiles, and organization management. Per Menlo Ventures, over 95% of customers adopt all three core components (source: menlovc.com). It supports 20+ social login providers, passwordless auth, MFA, and passkeys out of the box. Implementation time drops from weeks to hours, and the platform now manages 200M+ users across 15,000+ apps.

Clerk provides embeddable React components and backend SDKs that handle the full authentication flow. Developers add components like SignIn and UserButton to their frontend, and Clerk manages sessions, tokens, and user data server-side. It supports Next.js middleware for route protection and offers webhook integrations for syncing user events with external systems.

Based on TechnologyChecker.io detection data, companies using Clerk include Klaviyo (marketing automation, public company), Trustpilot (review platform), Bufab Group (Swedish industrial distributor), PanzerGlass (Danish electronics), and Qwilr (Australian proposal software). Clerk's own case study features Trading Experts (source: clerk.com/blog/trading-experts). Ramp's vendor data shows Clerk ranked #4 in identity provider adoption (source: ramp.com/vendors/clerk).

Yes, Clerk's free Hobby plan supports commercial applications with up to 50,000 monthly retained users per app. There are no revenue-sharing fees. The free tier includes most authentication features needed for production apps, though some features like custom session durations, allowlists, and advanced organization management require a Pro or Enterprise plan.

Clerk focuses on pre-built UI components and developer experience for modern React frameworks; Auth0 offers enterprise features like universal login and extensive identity protocols. On detected domains Clerk now leads: 8,315 against Auth0's 4,812. The clearer difference is who buys each. Clerk puts 76.25% of its customers in the 1-10 employee band and shows Next.js on 74.65% of its domains; Auth0 puts 37.71% at 1-10, 18.04% at 51-200, and shows Next.js on 19.74%. Clerk's free tier covers 10,000 monthly active users; Auth0's covers 25,000.

Yes, Next.js is Clerk's primary supported framework. Clerk provides a dedicated @clerk/nextjs package with middleware for route protection, server-side auth helpers, and App Router support. The integration works with both Server Components and Client Components. Clerk also supports React, Remix, Expo, and other modern JavaScript frameworks.

Yes, Clerk supports multiple passwordless methods including email magic links, SMS one-time passcodes, passkeys (WebAuthn), and social login via 20+ providers like Google, GitHub, Apple, and Microsoft. Passwordless auth is available on all plans including the free Hobby tier, with MFA as an optional additional security layer.

Clerk provides official SDKs for Next.js, React, Remix, Expo (React Native), Astro, and vanilla JavaScript. Backend SDKs are available for Node.js, Python, Go, and Ruby. The platform also offers a generic JavaScript SDK for frameworks without dedicated support. Next.js and React receive the most frequent updates and deepest integration support.

Yes, Clerk's Organizations feature provides multi-tenant auth with role-based access control, team management, and organization switching. Users can belong to multiple organizations and switch between them. The B2B Authentication add-on covers up to 100 monthly retained organizations on the free tier, with per-organization billing beyond that.

MRU stands for Monthly Retained User. Clerk only charges for users who return to your app at least one day after signing up. Users who sign up and never come back are free through the 'First Day Free' policy. This approach avoids charges for inactive signups and trial users who don't convert, reducing costs for apps with high signup-to-churn ratios.

Clerk focuses on pre-built UI components and user management; Firebase Authentication is part of Google's broader Firebase platform with tighter integration to Firestore and Cloud Functions. In our data Clerk reads 8,315 detected domains. Firebase appears on 1.53% of the domains that run Clerk, and of the 1,012 domains that dropped Clerk only 12 picked up Firebase — with 93% of Clerk-and-Firebase pairs still running both, the two coexist far more often than one replaces the other.

Migration assistance is included with Clerk's Enterprise plan. For self-service migration, Clerk provides documentation covering user import from Auth0, Firebase, Supabase, and custom databases. The migration process supports importing password hashes so users don't need to reset passwords. Clerk also offers a migration CLI tool for bulk user imports.