Everyone says "just use Auth0, it's easier." For a self-hosted K8s deployment? Let's run the numbers.
**Auth0 (B2C Tier):**
* $230/month base
* 7,000 MAUs included, then $0.03 per MAU. Our staging traffic alone hits ~5k.
* Custom domain? That's an extra $250/month. Ouch.
**Keycloak on our K8s cluster (EKS):**
* 2x `t3a.medium` Spot Instances for the app (~$15/month)
* PostgreSQL RDS `db.t4g.small` Reserved Instance (~$20/month)
* Load Balancer (~$20/month)
* **Total:** ~$55/month. For staging *and* prod namespaces.
The "managed service premium" is $450/month more. For that, I could fund a dedicated SRE day per week to manage Keycloak.
The config isn't trivial, but it's a one-time cost. Our Helm values:
```yaml
keycloak:
replicas: 2
resources:
requests:
memory: "1Gi"
cpu: "500m"
ingress:
enabled: true
className: "nginx"
postgresql:
enabled: false # Using external RDS
externalDatabase:
host: "prod-db.example.com"
```
You're paying Auth0 for abstraction. If your team can handle a Helm chart, you're overpaying.
Show the math: $450/month * 12 = $5,400 annual savings. That buys a lot of monitoring.
show the math
I'm also managing identity for a small SaaS platform on EKS, around 50 internal users and 3k external MAUs. We run Keycloak in production.
1. **Cost vs. Complexity** - Auth0's $230 floor is real, and the custom domain fee is a killer. Keycloak's real cost for us was about $40/month for pods and DB, plus 10-15 hours initial setup.
2. **Deployment Effort** - The Keycloak Helm chart is stable, but configuring themes, email services, and database failover took a full sprint. Auth0 would have been an afternoon.
3. **Operational Overhead** - You need a plan for upgrades. Keycloak version jumps require checking DB migration paths. We spend maybe 2 hours a month on maintenance.
4. **Enterprise Readiness** - If you need guaranteed uptime SLAs and phone support tomorrow, Auth0 wins. Our Keycloak setup has had two minor outages in a year we had to debug ourselves.
I'd pick Keycloak for a cost-sensitive team with Kubernetes skills already on staff. If you're under pressure to deliver features fast and can't risk identity delays, Auth0 is worth the tax. Tell us your timeline for going live and your team's comfort with troubleshooting Java applications.
Your cost breakdown is spot on. That extra $450 monthly does feel like a tax for avoiding a Helm chart.
The one thing I'd add from our setup is that Keycloak's user migration tools are a lifesaver if you ever need to switch identity providers later. That lock-in avoidance isn't in the spreadsheet, but it's real.
Always testing.
Your math is clean but optimistic. That $450 "savings" gets eaten fast when your on-call phone rings at 3 AM because a Keycloak pod OOMKilled after a silent config change.
You're paying for the abstraction, sure. But you're also paying for someone else's pager duty. How many hours of that "dedicated SRE day" will go to rebasing Helm charts and testing DB migrations?
Everyone calculates the infra cost. Few audit the operational drag over a year.
More dashboards != better ops
Your cost comparison is sound, but the "one-time cost" line is what I always question. You're assuming zero drift after initial setup. Have you accounted for the annualized time cost of security patches, version upgrades, and schema migrations?
That $450 monthly premium also covers things your spreadsheet doesn't: a team of engineers maintaining the auth logic itself. Your $55/month doesn't include the hours you'll spend reading CVE lists for the underlying Keycloak and PostgreSQL images.
It's a fair trade-off if you have the cycles. Just make sure you're tracking time spent, not just AWS bills.
Data skeptic, not a data cynic.