Working across both AWS and Azure environments over the years, I’ve had to make this call more than once: Azure Key Vault or AWS Secrets Manager? On the surface they solve the same problem — keeping credentials, keys, and certificates out of your source code — but the details of how each integrates with its native cloud, and what else they can do beyond basic secret storage, matter a lot once you’re actually building on top of them.
Quick Overview
Azure Key Vault is Microsoft’s managed service for storing secrets, encryption keys, and certificates, tightly integrated with Azure Active Directory (Entra ID) and the broader Azure ecosystem.
AWS Secrets Manager is AWS’s managed secrets storage and rotation service, tightly integrated with IAM and AWS-native services like RDS and Lambda.
Both are fully managed — neither requires you to run your own infrastructure, unlike HashiCorp Vault, which I compare separately in more depth.
Key Differences
Scope: Secrets vs Keys vs Certificates
Azure Key Vault is explicitly designed around three distinct object types — secrets, keys, and certificates — each with its own access model and, in the case of keys, hardware security module (HSM) backing for cryptographic operations. AWS Secrets Manager is more narrowly focused on secrets specifically; for encryption keys, AWS separates that concern into a different service (KMS), and for certificates, into AWS Certificate Manager.
If you want one unified service covering secrets, keys, and certificates together, Azure Key Vault’s combined model is more convenient. If you’re fine using purpose-specific AWS services for each (Secrets Manager, KMS, ACM), the AWS approach gives you more specialized tooling per use case.
Identity Integration
Azure Key Vault integrates with Azure Active Directory (Entra ID) for access control, using the same identity and role-based access control (RBAC) model you’d use elsewhere in Azure. AWS Secrets Manager uses IAM policies in the same way. Both are strong integrations — the choice mostly comes down to whichever identity platform your organization is already standardized on.
Rotation
Both support automatic secret rotation, but the mechanics differ slightly. AWS Secrets Manager uses Lambda functions to perform custom rotation logic. Azure Key Vault supports rotation policies and integrates with Azure Functions for custom rotation logic in a similar pattern.
Pricing
Azure Key Vault pricing is based on the number of operations and whether you’re using standard (software-protected) or premium (HSM-backed) tiers. AWS Secrets Manager charges per secret stored plus API calls. Neither is dramatically more expensive than the other for typical usage, though HSM-backed keys in Key Vault’s premium tier add meaningful cost if you need that level of protection.
Architecture Comparison
flowchart TD
subgraph Azure Key Vault
A1[Application] --> A2[Azure AD / Entra ID Auth]
A2 --> A3[RBAC or Access Policy Check]
A3 --> A4[Secret, Key, or Certificate Returned]
end
subgraph AWS Secrets Manager
B1[Application] --> B2[IAM Authentication]
B2 --> B3[IAM Policy Check]
B3 --> B4[Secret Returned + Lambda-based Rotation]
end
When Azure Key Vault Makes More Sense
- Your organization runs primarily on Azure and already uses Entra ID for identity.
- You need a single service that handles secrets, encryption keys, and certificates together.
- You need HSM-backed key protection for compliance requirements.
- You’re integrating with Azure-native services like App Service, Azure Functions, or AKS.
When AWS Secrets Manager Makes More Sense
- Your organization runs primarily on AWS and already uses IAM for identity and access management.
- You want tight, native integration with RDS, Lambda, and other AWS-native services for automatic credential rotation.
- Your needs are focused specifically on application secrets rather than broader key and certificate management.
Best Practices for Either Platform
- Enable automatic rotation wherever your workload supports it.
- Apply least-privilege access — scope permissions to specific secrets/vaults rather than granting broad access.
- Enable diagnostic/audit logging and route it to a monitoring system you actually review.
- Separate secrets by environment (dev, staging, prod) using distinct vaults or resource-level access boundaries.
- Avoid hardcoding secrets even temporarily during local development — use the managed service’s local emulation or CLI tools instead.
Common Mistakes
- Granting overly broad access policies on a vault “to save time,” rather than scoping access per application or team.
- Not enabling soft-delete and purge protection (Key Vault) or recovery windows (Secrets Manager), which can make accidental deletions unrecoverable.
- Mixing secrets from multiple environments in a single vault or secret store, increasing blast radius if compromised.
- Forgetting that certificates and keys have their own lifecycle and expiration separate from application secrets, and need their own monitoring.
FAQs
Can I use both if I run workloads on both Azure and AWS? Yes, and many hybrid or multi-cloud organizations do exactly that, sometimes alongside a cloud-agnostic layer like Vault to reduce the operational complexity of managing two entirely separate secrets platforms and policies.
Is Azure Key Vault better for certificate management than AWS? Generally, yes, in the sense that it’s unified with secrets and keys in one service, whereas AWS splits certificate management into a separate service (ACM). Neither is objectively worse — it’s a difference in how each cloud organizes related capabilities.
Do I need the premium (HSM-backed) tier of Key Vault? Only if you have a specific compliance or security requirement for hardware-backed key protection. For most standard application secrets, the standard tier is sufficient.
Conclusion
Azure Key Vault and AWS Secrets Manager are both mature, well-integrated options — the right choice depends almost entirely on which cloud (and which identity platform) your organization is built around. If you need a single service spanning secrets, keys, and certificates, Key Vault’s combined model has an edge. If your priority is tight native integration with AWS services and IAM, Secrets Manager is the more natural fit.
