アーキテクチャ・意思決定比較表
Auth0 と Logto のデータ構造、運用コスト、ライセンスリスクの違いを詳細に分析します。
While Auth0 remains an industry standard for identity and access management (IAM), many organizations face severe budget strain due to its steeply scaling Monthly Active User (MAU) pricing tiers. As teams scale, Auth0’s cost structure can quickly outpace core infrastructure spend, prompting engineering leads and financial planners to look for self-hosted, developer-friendly open-source alternatives like Logto.
Auth0 Official Pricing Plans
Auth0’s pricing is structured primarily around Monthly Active Users (MAUs). Below is the official breakdown of their current standard plans as of June 2026:
| Plan Name | Monthly Cost (Starts at) | Annual-Equivalent Monthly Cost | Key Highlights | Target Audience |
|---|---|---|---|---|
| Free Tier | $0 | $0 | Up to 7,500 MAUs, basic login box, up to 3 social connections, community support. | Hobbyists and early MVP prototyping. |
| Essentials | $23 / month | $23 / month | Starts at 500 MAUs. Custom domains, up to 3 enterprise connections, basic Multi-Factor Authentication (MFA), Auth0 Actions. | Early-stage startups requiring custom branding. |
| Professional | $130 / month | $130 / month | Starts at 500 MAUs. Unlimited enterprise connections, Advanced MFA (Push, WebAuthn), user management dashboards, Role-Based Access Control (RBAC). | Growth-stage SaaS products needing advanced security. |
| Enterprise | Custom | Custom | Unlimited scale, SLA guarantees, advanced enterprise SSO, dedicated support. | High-volume SaaS platforms and enterprise IT. |
Hidden Costs of Auth0
While the base pricing of Auth0 appears manageable at 500 MAUs, scaling your user base or adding standard operational workflows uncovers several hidden costs:
- MAU Tier Overages: Auth0 does not charge a flat rate; crossing into a higher MAU bracket (e.g., moving from 5,000 to 10,000 MAUs) trigger sharp pricing cliffs that can instantly triple your bill.
- Administrative & Team Seat Surcharges: Adding multiple engineering, support, or security seats to the Auth0 dashboard can incur additional licensing costs depending on your plan tier.
- MFA Communication Costs: SMS-based MFA is not included in the standard subscription; it is billed separately per-message based on regional carrier rates and volume, leading to unpredictable monthly bills.
- API Rate Limits: Exceeding standard API rate limits (such as during migrations or peak traffic events) requires upgrading to premium tiers or custom enterprise contracts to avoid throttling.
- Onboarding & Professional Services: Setting up complex enterprise federations (such as SAML integrations for enterprise clients) often requires expensive external consulting or specialized custom-tier add-ons.
Total Cost of Ownership (TCO) Analysis: Logto (Self-Hosted)
Logto is an AGPL-3.0 licensed, TypeScript-based open-source alternative designed to offer identical capabilities to Auth0 (such as multi-factor authentication, single sign-on, and polished UI components) without the proprietary price tag. However, self-hosting an IAM solution is not entirely free.
Cost Trade-offs at a Glance
1. Hosting & Server Resource Estimation
To run a production-ready, highly available Logto instance, your infrastructure must scale to meet user demand:
- Small Team (Up to 5,000 MAU): $30 – $50/month. Requires 1 small virtual machine (e.g., AWS t3.medium or a DigitalOcean Droplet) and a basic managed PostgreSQL database.
- Medium Team (Up to 50,000 MAU): $150 – $300/month. Requires 2 load-balanced app instances, a multi-AZ PostgreSQL database, and a small Redis cluster for session caching.
- Large Team (Up to 250,000+ MAU): $600 – $1,200/month. Requires an auto-scaling cluster (ECS/EKS), high-performance multi-region RDS database, Redis replication, and a CDN/WAF.
2. Maintenance & Engineering Support Estimation
Self-hosting means your engineering team is responsible for uptime, security patches, and database backups:
- Small Team: ~2 hours/month of developer time ($150–$300/month equivalent).
- Medium Team: ~5–8 hours/month of DevOps monitoring and patching ($500–$1,000/month equivalent).
- Large Team: ~15–20 hours/month of dedicated DevOps and security auditing ($1,500–$2,500/month equivalent).
Comparative TCO Table (SaaS Fees vs. Self-Host Infrastructure)
The table below outlines the realistic monthly costs of Auth0 compared to Logto (including hosting and maintenance overheads) as your scale expands:
| Scale (MAU) | Auth0 Estimated Monthly Cost | Logto Self-Host (Infra + Engineering Time) | Monthly Savings with Logto |
|---|---|---|---|
| 5,000 | $0 – $150 (Free/Essentials) | ~$200 (Minimal infra + 1hr dev maintenance) | Minimal / Break-even |
| 20,000 | $400 – $800 (Essentials/Professional) | ~$450 ($150 infra + $300 dev maintenance) | $0 – $350 |
| 100,000 | $2,500 – $4,500+ (Professional/Enterprise) | ~$1,300 ($500 infra + $800 dev maintenance) | $1,200 – $3,200 |
Scenarios: Cost Comparison by Team Size
Scenario A: 5-User Team (Early Stage MVP, < 7,500 MAUs)
- Auth0 Cost: $0/month. Under 7,500 MAUs, a small team can comfortably utilize Auth0’s Free Tier with basic social connections.
- Logto Cost: ~$50/month (Self-hosted on basic VPS for testing/development).
- Verdict: Auth0 wins on cost. For tiny projects, leveraging Auth0’s free tier avoids infrastructure setup overhead entirely.
Scenario B: 20-User Team (Growing SaaS, ~25,000 MAUs, Enterprise SSO requirements)
- Auth0 Cost: ~$1,200/month. To support enterprise connections (SSO) and advanced MFA for 25,000 MAUs, you must use the Professional plan, which charges heavy premiums as MAUs scale.
- Logto Cost: ~$500/month (Infrastructure: $150, Dev overhead: $350).
- Verdict: Logto wins. As soon as B2B enterprise features (SAML/SSO) are required, Auth0’s Professional plan scaling becomes highly inefficient.
Scenario C: 100-User Team / Mid-Sized Enterprise (150,000+ MAUs, Advanced Customizations)
- Auth0 Cost: $5,000+ / month (Requires an Enterprise Custom Contract).
- Logto Cost: ~$1,800/month (Infrastructure: $800, DevOps maintenance: $1,000).
- Verdict: Logto wins decisively. The self-hosted model caps software licensing fees at $0, meaning budget is directed purely toward robust AWS/GCP hosting infrastructure.
When Does Paying for Auth0 Actually Save Money?
Despite the higher price tag, Auth0 can be the more economical choice under specific business conditions:
- Strict Compliance Demands: If your customers require SOC 2 Type II, HIPAA, or ISO 27001 compliance immediately, Auth0 provides these certifications out-of-the-box, saving you months of expensive compliance auditing.
- Zero In-House DevOps Capability: If your engineering team is purely focused on product development and lacks the bandwidth or expertise to manage, secure, and update an IAM cluster, the risk of a self-hosted database breach far outweighs the SaaS subscription fee.
- Speed to Market: When launching an MVP, using Auth0’s pre-built SDKs can shave weeks off development, allowing you to validate your product faster.
Final Purchasing Recommendation
- Choose Auth0 if you are a small startup with under 7,500 active users, or an enterprise that demands instant SOC 2 compliance, zero maintenance overhead, and has the budget to support custom contract pricing.
- Choose Logto (Self-Hosted) if you are a growth-stage startup or developer-centric engineering team experiencing rapid user growth, require unlimited enterprise SSO connections without paying exorbitant premiums, and want complete sovereignty over your user data.
Cost and pricing analysis verified as of 2026-06-25. Self-hosting costs are estimates based on standard cloud providers.
よくある質問
If my application grows beyond Auth0's free tier of 7,500 Monthly Active Users (MAU), how does pricing scale and what hidden costs should I expect?
Once you exceed Auth0's 7,500 MAU free limit, you must transition to paid plans like Essentials starting at $23/month or Professional starting at $130/month, both of which only include 500 MAUs before additional overage fees apply. Furthermore, you will face hidden costs such as per-message volume billing for SMS-based MFA and the requirement of custom enterprise contracts for high-level features. In contrast, Logto's AGPL-3.0 licensed codebase allows you to self-host to avoid these scaling and overage fees entirely while matching Auth0 with a 9/10 feature overlap score.
What security and integration features are restricted to Auth0's higher pricing tiers, and how does Logto compare?
Auth0 restricts custom domains and limits you to just 3 enterprise connections on its $23/month Essentials tier, while advanced Multi-Factor Authentication like push notifications or WebAuthn and Role-Based Access Control (RBAC) require upgrading to the $130/month Professional tier. Because Logto is an open-source alternative built on TypeScript, you can deploy these exact authentication, MFA, and SSO capabilities yourself under the AGPL-3.0 license. This self-hosted model eliminates the rapid pricing escalation that occurs as you unlock standard security standards on Auth0.
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機能と価格データは公式ドキュメントと料金ページを出典としており、最終確認日は 2026年6月25日 です。 誤りを見つけましたか？お知らせいただければ修正します。