Alternatives
10 best Castle alternatives
Tools that cover the same task as Castle (security), ranked by how completely their pricing, free tier and API access are documented. Checked Oct 4, 2026.
- Castle starts at
- $200/mo
- Free plan
- Free plan
- API
- API available
- 01
Aserto
Aserto provides cloud-native authorization as a service with fine-grained RBAC, ABAC, or ACL enforced in about a millisecond. Developers use SDKs, policy repositories, and authorizer instances to centralize permissions for applications and APIs.
Best for: Teams adding centralized, low-latency authorization to SaaS apps, especially alongside Auth0 or similar identity providers.
- 02
WorkOS
WorkOS helps SaaS companies add enterprise-ready authentication features such as SSO, Directory Sync, MFA, Audit Logs, and AuthKit user management with minimal integration code. The platform targets staging and production environments with modular APIs for B2B customer IT requirements.
Best for: B2B software vendors selling to enterprise customers who need SSO, SCIM, compliance logging, and self-serve IT onboarding.
- 03
Ory
Ory provides identity, authentication, authorization, and OAuth2/OIDC services through Ory Network and related open-source projects such as Kratos, Hydra, and Keto. The commercial site targets CIAM, B2B IAM, fine-grained permissions, passkeys, and enterprise SSO for applications that need scalable, API-first identity infrastructure.
Best for: Product and platform teams replacing Auth0-style stacks or self-hosting Ory components who need hosted Ory Network production environments.
- 04
Cloudanix
Cloudanix is a CNAPP+ platform spanning code, cloud, access, and agentic security on one graph. It offers CSPM, CIEM, workload protection, just-in-time access, coding-agent guardrails, and LLM-native investigation across AWS, Azure, GCP, and Kubernetes with self-serve Pro SKUs and enterprise options.
Best for: Security and platform engineering teams needing unified cloud posture, runtime protection, JIT access, and guardrails for AI coding agents.
- 05
Pritunl
Pritunl is an open-source enterprise VPN platform for OpenVPN, WireGuard, and IPsec with a web management UI, multi-host clustering over MongoDB, and optional premium features such as SSO and site-to-site links. It targets self-hosted remote access and VPC peering across clouds.
Best for: Infrastructure teams needing self-hosted VPN with horizontal scaling and enterprise authentication options.
- 06
Bubble
Bubble is a visual no-code platform for building web and mobile applications with databases, workflows, design tools, and AI-assisted development in a hosted workspace.
Best for: Founders and product teams shipping full-stack apps without traditional code who need Bubble-hosted infrastructure.
- 07
AppSpector
AppSpector is a remote debugging platform for iOS and Android apps. It gives engineering, QA, and support teams live access to device sessions, network traffic, logs, and other in-app internals so hard-to-reproduce bugs can be diagnosed without physical access to the user device.
Best for: Mobile teams that need remote session inspection across QA, support, and distributed engineering workflows.
- 08
ngrok
ngrok is cloud networking infrastructure that routes and secures traffic to apps, APIs, and AI workloads on localhost, private networks, or production clusters. The official site positions it as an ingress platform with tunnels, a global edge, API gateway features, and Kubernetes ingress so developers can expose services safely without rebuilding networking for each environment.
Best for: Developers and platform teams that need secure public URLs, ingress, and traffic policy for local dev, webhooks, and production APIs.
- 09
IP2Location.io
IP2Location.io provides IP geolocation, proxy detection, and related APIs including bulk queries, WHOIS, and hosted domain lookups. Subscription plans scale monthly query allotments for geolocation, WHOIS, and hosted domain endpoints.
Best for: Developers adding IP geolocation, fraud signals, or localization to apps, security stacks, or marketing tooling.
- 10
Blynk
Blynk is a low-code IoT platform for building mobile apps, web dashboards, and device fleets. Companies connect hardware over MQTT, HTTP, and webhooks while managing provisioning, automations, and multi-tenant organizations in managed cloud.
Best for: Product teams shipping connected devices who need branded apps and cloud device management without custom backend work.
Castle alternatives: common questions
What is the best free alternative to Castle?
Aserto has an ongoing free plan. Starter tier is FREE forever with limits on policy repositories, authorizer instances, and users. Free plans change, so check the vendor before relying on one.
What is the cheapest Castle alternative?
Aserto has the lowest listed starting price at $0.20/mo, compared with $200/mo for Castle.
Which Castle alternatives have an API?
Aserto, WorkOS, Ory, Cloudanix, Pritunl mention API or developer access.