Companies Using Auth0

With over a decade of experience in web crawling and technographic data analysis, I've examined Auth0's position in the identity-as-a-service market using our enriched dataset of 3,632 companies matched from 4,812 active detections, as of our March 2026 crawl. Auth0 was co-founded in 2013 by Eugenio Pace and Matias Woloski (source: auth0.com/blog/announcing-auth0), raised over $210 million across six funding rounds (source: VentureBeat), and was acquired by Okta for $6.5 billion in May 2021. The platform now processes 2.5 billion authentications per month (source: auth0.com). Here's what the data reveals.

Growth trajectory

Auth0's adoption curve has two distinct phases. From 2014 to mid-2021, growth was organic and steady, reaching just 455 active domains over seven years. Then between July and October 2021, active domains jumped from 455 to 2,220, coinciding with Okta's acquisition. By December 2024, Auth0 hit its all-time peak of 6,831 active domains. That's a 15x increase in just three years.

One data point that explains why companies keep buying identity infrastructure: Auth0's 2025 Customer Identity Trends Report found that 46.1% of all new signups across the platform met criteria for a fraudulent attack (source: auth0.com/customer-identity-trends-report). And 16.9% of login attempts showed clear malicious behavior. Building this detection in-house is expensive; buying it from Auth0 isn't.

"The 2021 spike wasn't organic product-market fit. It was Okta's sales machine cross-selling Auth0 into its enterprise customer base. The real question is whether that growth sticks." - Mehmet Suleyman, CEO at TechnologyChecker.io

Sales Signal: Auth0's rapid post-acquisition growth means there's a large cohort of relatively new customers (2021-2024 adopters) still evaluating the platform. These companies are in the consideration window for complementary identity tools, migration services, and integration consulting.

Customer profile

Auth0's size curve is the flattest in the identity category, and it is the single clearest way to distinguish Auth0 from Clerk. 37.71% of Auth0's matched companies have 1-10 employees, 29.61% have 11-50, 18.04% have 51-200 and 7.15% have 201-500. A visible tail runs above that: 0.56% at 5,001-10,000 and 0.64% at 10,001+, which in absolute terms means household enterprise names.

Clerk's equivalent distribution puts 76.25% in the 1-10 band and 4.04% at 51-200. The two products occupy one category and sell to almost disjoint populations: Auth0 is bought where there is a procurement process, Clerk where there is not.

By founding decade Auth0's base splits 37.98% in the 2010s and 33.55% in the 2020s, against Clerk's 63.18% in the 2020s alone. Auth0's customers are older companies with existing web estates to put a login in front of.

Sales Signal: Auth0's mid-market band (51-500 employees, 25.19% of the base) is the segment that neither Clerk nor Okta owns cleanly. That is where competitive displacement is most likely to be winnable.

Industry and geographic concentration

Software Development leads at 23.28%, followed by Technology, Information & Internet at 9.37% — together 32.65% of the matched base. Financial Services at 7.83% is the third vertical and the most commercially interesting one: identity products sell hardest where compliance requirements make authentication a board-level concern. IT Services (5.25%), Insurance (2.47%) and Hospitals & Health Care (1.65%) follow.

Geographically, the United States leads with 57.22%, ahead of the United Kingdom at 9.69%, Canada at 6.10%, Australia at 5.85% and Germany at 4.10%. The Nordics are represented but small — Sweden 1.72%, Norway 1.49%, Denmark 1.27%.

Sales Signal: the financial-services and insurance block (10.3% combined) is Auth0's highest-value segment. Those buyers have compliance budgets, long contracts, and no appetite for the build-it-yourself alternative that Clerk's base is comfortable with.

Migration patterns

Auth0 shows no outbound corridor. 332 domains dropped Auth0 since March 2026, and across the seven destinations I tested — Clerk, NextAuth.js, Okta, Amazon Cognito, Microsoft Entra ID, Auth0 Lock and Firebase — the largest flow was seven domains to NextAuth.js, below the volume at which I will publish a claim.

Two results are worth keeping anyway. Not one of the 332 departures moved to Clerk, despite Clerk and Auth0 being the most frequently compared pair in the category. And the largest movement anywhere near Auth0 runs inward from its own legacy widget: 44 domains dropped Auth0 Lock while keeping Auth0, against 2 the other way, with 100% of the pairs still running both. That is a version migration inside one product, not churn — and it is exactly the kind of signal that gets misreported as a competitive win when nobody checks the direction.

Sales Signal: Auth0's retention is strong on this evidence. The competitive pressure from Clerk is not showing up as displacement; it is showing up in which product new companies pick, which is a different sales problem.

Technology ecosystem

Auth0's co-occurrence profile is broader and older than Clerk's, which is exactly what a platform deployed in front of an existing web estate should look like. Google Analytics appears on 64.42% of Auth0 domains, Google Tag Manager on 64.35%, jQuery on 55.38% and core-js on 54.58%. WordPress runs 25.8% and Bootstrap 24.45%, while Next.js reaches only 19.74% and React 10.3%.

The defensive layer is the distinctive part: reCAPTCHA on 52.93% and Cloudflare Bot Management on 21.74%, with Cloudflare itself at 68.31%. Login pages attract automated traffic, and Auth0's customers put something in front of them. Clerk's base shows no comparable bot-defence concentration.

The marketing layer is also present in a way it is not for Clerk — HubSpot at 26.25%, LinkedIn Insight Tag at 21.65%, DoubleClick Floodlight at 23.2%, Facebook Pixel at 22.73%. These are companies running demand generation, which is another way of saying they have a sales motion.

G2 review signals

G2 reviews show ease of use as the top positive signal (47 mentions), followed by security features (37 mentions) and flexibility (39 mentions). The ease-of-use praise aligns with specific vendor case studies: Flo Health's CTO Roman Bugaev said "authentication is kind of a solved problem already, and we realized we just needed to take the best solution from the market" (source: auth0.com/case-studies/flo-health). Dunelm's Head of Data Platforms, Antony Sohal, put it more bluntly: "Auth0 can do authentication much better than we can" (source: auth0.com/case-studies/dunelm).

On the negative side, pricing complexity leads with 42 mentions. Our switching data does not corroborate a cost-driven exodus, though: none of the 332 domains that dropped Auth0 since March 2026 picked up Amazon Cognito. Variable customer support quality (26 mentions) aligns with Auth0's tiered model where free and Essentials plans get community support only. A SecurityBoulevard article (2025) specifically documents developer frustration with post-acquisition support quality.

Sales Signal: Pricing is the #1 complaint and migration to cheaper alternatives is measurable in our data. Auth0's free tier offers 25,000 MAUs, but the jump to paid starts at $35/month for just 500 MAUs (source: auth0.com/pricing). Companies growing past 10,000 MAUs on the Professional plan ($240/month for 500 MAUs) face steep increases. These companies are prime targets for pricing-competitive alternatives.

Key takeaways

1. Auth0 ranks #3 in Authentication & SSO with 4,812 active domains and 1.22% market share, trailing only Azure AD and Amazon Cognito.

2. The post-acquisition growth was dramatic: 15x increase from mid-2021 to late 2024, driven by Okta's enterprise sales channel. Okta + Auth0 now serve 18,000+ customers combined (source: Okta ESG Report 2024).

3. Small teams dominate: 66% of customers have fewer than 50 employees, but Fortune 500 companies like Siemens, Pfizer, and P&G validate enterprise capability.

4. Auth0 is a net gainer from all competitors, with the strongest migration flow from Azure AD (1.8:1 gain ratio). This reflects the industry-wide shift toward separating workforce and customer identity.

5. Vendor case studies show real ROI: 12.5x sign-up growth (Flo Health), €2,500/day savings (HolidayCheck), 300% ROI (Nordcloud), and 8-10 FTE saved (Dunelm). These are verifiable claims published on auth0.com.

6. Auth0 for AI Agents (launched April 2025) positions the platform for agentic workflows with Token Vault, async authorization, and fine-grained access for RAG. This could reshape how identity infrastructure serves the next generation of applications.

Sales applications

For prospecting, filter TechnologyChecker.io for companies using Auth0 in the 11-50 employee range, founded 2015-2022, in Software Development or Financial Services. These companies are likely outgrowing the free tier and evaluating paid plans or alternatives.

Outreach template: "Hi [Name], I noticed [Company] uses Auth0 for authentication. With [X] employees and growing, you're likely hitting the MAU pricing tiers. Our [product/service] helps Auth0 customers [specific benefit]. Companies like [similar company from our data] reduced their identity costs by [X%] after [specific action]."

Competitive angle: we found no measurable corridor out of Auth0 to any competitor. Target companies in the 1,000-10,000 MAU range on Auth0's Professional plan, where the price-per-user gap widens most.

For the complete dataset of 3,632 enriched Auth0 companies with industry, size, and location filters, visit TechnologyChecker.io's Auth0 technology page.