Auth0
Okta · Ranked #1 of 8 in Authentication & Identity APIs
The category-defining developer-first identity platform, now Okta-owned, with deep docs, extensibility (Actions/Rules) and a 99.99% public-cloud SLA.
Full-featured CIAM for B2C and B2B
Overview
Auth0 (now owned by Okta, which acquired it in 2021 for ~$6.5B) is one of the most widely adopted developer-first identity platforms, spanning Customer Identity (CIAM) for both B2C and B2B applications. Its core proposition is to let teams outsource authentication, authorization, SSO, MFA, and user management to a hosted, standards-based service (OAuth 2.0, OIDC, SAML) rather than building it in-house. The flagship Universal Login centralizes the login experience, and the platform is extended through Actions (serverless JavaScript hooks in the auth pipeline), an extensive Management API, and 30+ SDKs/Quickstarts. It is a clear leader in G2's IAM/CIAM/SSO categories and is trusted by a large base of startups through enterprises.
Auth0's biggest strength is developer experience and breadth: drop-in SDKs for nearly every major framework, mature documentation, social/enterprise connections, anomaly/attack protection, and strong reliability (Auth0 reports five-nines uptime across its US public cloud over the trailing 12 months against a contractual 99.99% Enterprise SLA). Where it draws the most criticism is pricing. The model is MAU-based with hard caps and feature gating, and post-Okta pricing changes have been widely characterized by developers as steep and unpredictable, including reports of large bill increases and a B2C Essentials price jump. B2B-critical capabilities (enterprise SSO connections, higher rate limits, custom SLA, private cloud) are concentrated in the custom-priced Enterprise tier, which startups frequently describe as a "growth penalty."
Net: Auth0 is an excellent default for teams that want best-in-class, standards-compliant identity with minimal engineering lift, especially when they value reliability and ecosystem maturity over cost predictability. Cost-sensitive startups scaling MAUs, or B2B SaaS needing many enterprise SSO connections, often hit pricing friction and evaluate alternatives (Clerk, Supabase Auth, Keycloak/FusionAuth, WorkOS, Logto), making Auth0 strongest for mid-market and enterprise buyers who prioritize a proven, well-supported platform.
How this score is derived
The APIbenchmarks Index is a weighted sum of four dimensions, each scored on an absolute 0–100 reference scale. See the methodology for every mapping.
| Dimension | Score | Weight | Contribution |
|---|---|---|---|
| Documentation & DXExtensive docs, 30+ SDKs/Quickstarts and per-framework interactive guides, though some developers report the docs can be confusing and inconsistent in places. | 93 | 30% | 27.9 |
| ReliabilityContractual 99.99% Enterprise SLA with service credits, and Auth0 reports 99.999%+ trailing-12-month uptime across its US public cloud via a public status page. | 92 | 25% | 23.0 |
| Ecosystem & SDKsMature ecosystem with 45+ open-source SDK libraries across ~12 languages, deep OAuth/OIDC/SAML standards support, and Okta-backed enterprise integrations. | 95 | 25% | 23.8 |
| AccessibilityGenerous free tier (up to 25,000 B2C MAUs) and self-serve onboarding make entry easy, but MAU caps and Enterprise-gated features limit accessibility at scale. | 85 | 20% | 17.0 |
| APIbenchmarks Index (ABI) | 91.7 | ||
Table 1. Derivation of the ABI for Auth0. Contribution = score × weight; the index is their sum.
At a glance
- Vendor
- Okta
- Pricing model
- MAU-based
- Free tier
- 25k MAU (free plan)
- Official SDKs
- 12 languages
Pricing
| Free | $0 | Up to 25,000 MAU (B2C) / 500 MAU (B2B); includes social connections, basic MFA, and community support. |
| B2C Essentials | from $35-$70/mo (500 MAU) | Adds passwordless, MFA, role-based access; entry price for B2C scaled to MAU (raised toward $70/mo in late 2025). |
| B2B Essentials | from $150/mo (500 MAU) | Organizations support (unlimited orgs), B2B-oriented features, scaled by MAU. |
| B2C Professional | from $240/mo (1,000 MAU) | Adds external user databases, more MFA options (phone/email/WebAuthn/Guardian push), enhanced attack protection, longer log retention. |
| B2B Professional | from $800/mo (1,000 MAU) | Professional feature set for B2B with organizations and advanced protection, scaled by MAU. |
| Enterprise | Custom | Custom user/SSO tiers, 99.99% SLA, enterprise rate limits, advanced admin/support, private cloud options. |
Key features
- •Universal Login (centralized, customizable hosted login)
- •Actions (serverless JavaScript hooks in the auth pipeline)
- •Multi-factor authentication (SMS/email, WebAuthn, push via Guardian, TOTP)
- •Single Sign-On (SSO) and enterprise connections (SAML, OIDC, AD/LDAP)
- •Social and passwordless login
- •Attack protection (brute-force, breached-password detection, bot detection)
- •B2B Organizations (multi-tenant org management)
- •Management API and extensive RBAC/roles
- •Fine Grained Authorization (FGA) for relationship-based access
- •Custom domains, branding, and log streaming
Official SDKs
Strengths & trade-offs
- +Best-in-class developer experience with 30+ SDKs/Quickstarts covering nearly every major framework
- +Universal Login plus Actions allow MFA, social login, and custom pipeline logic without app code changes
- +Strong standards support (OAuth 2.0, OIDC, SAML) and deep enterprise SSO/identity connections
- +Proven reliability: 99.99% Enterprise SLA and reported 99.999%+ trailing-12-month US cloud uptime
- +Generous free tier (up to 25,000 B2C MAUs) lowers the barrier to start
- +G2 Leader across CIAM, IAM, SSO, MFA, and user provisioning categories
- –MAU-based pricing with hard caps gets expensive fast at scale; widely called a startup 'growth penalty'
- –Post-Okta pricing changes seen as steep and unpredictable (reports of large bill jumps and a B2C Essentials hike)
- –B2B-critical features (enterprise SSO connections, higher rate limits, custom SLA, private cloud) gated behind custom Enterprise pricing
- –Developers report documentation can be confusing and support sometimes unresponsive
- –Some reports of declining quality/reliability perceptions and bugs post-acquisition
What developers say
G2 4.3/5 (~266 reviews)
Developers praise Auth0's ease of integration, SDK breadth, and reliability, but pricing, especially post-Okta MAU-based increases, is the dominant and recurring complaint.
“Users consistently praise Auth0 for its ease of use and flexibility in implementing secure authentication, with Single Sign-On scoring 9.1 and MFA 9.0.”
Key figures
| Enterprise availability SLA | 99.99% / month (with service credits) | Auth0 SLA documentation ↗ |
| Reported trailing-12-month uptime (US public cloud) | 99.999%+ (five nines) | Auth0 blog (availability guarantee) ↗ |
| Free tier MAU limit (B2C) | 25,000 MAU | Auth0 pricing page ↗ |
| B2C Professional entry price | $240/mo for 1,000 MAU | Auth0 pricing page ↗ |
| B2B Professional entry price | $800/mo for 1,000 MAU | Auth0 pricing page ↗ |
| G2 aggregate rating | 4.3 / 5 (~266 reviews) | G2 ↗ |
Compare Auth0 head to head
Sources
- https://auth0.com/pricing
- https://auth0.com/docs/troubleshoot/customer-support/services-level-descriptions
- https://auth0.com/blog/auth0-guarantees-99-99-availability-on-public-cloud/
- https://status.auth0.com/
- https://auth0.com/docs/libraries
- https://www.g2.com/products/auth0/reviews
- https://ssojet.com/blog/auth0-complaints-reddit-developers
- https://securityboulevard.com/2025/09/top-10-auth0-complaints-developers-post-on-reddit-analysed/
- https://ssojet.com/blog/auth0-pricing-growth-penalty
Figures last verified 2026-06-27. Spotted an error? corrections@apibenchmarks.com