How HashiCorp Vault and Google Cloud KMS differ on scope, key custody, deployment and cost.
| HashiCorp Vault | Google Cloud KMS | |
|---|---|---|
| Type | Secrets platform | Cloud KMS |
| Scope | Secrets, keys, PKI, dynamic credentials | Encryption keys |
| Deployment | Self-hosted + HCP | SaaS (GCP) |
| Key custody | HSM auto-unseal and seal wrap in Enterprise | HSM tier FIPS 140-2 Level 3; External Key Manager for off-cloud keys |
| How it works | A secrets engine rather than a key store: it issues short-lived database credentials, cloud tokens and certificates on demand, so secrets expire instead of sitting in a config file. Transit lets it act as an encryption service too. Powerful, and heavy to run properly. | Key rings and key versions with explicit rotation, offered in software, HSM and external tiers. External Key Manager is the differentiator: the key stays in your own system and Google calls out to it, so the cloud can be denied access by design rather than by policy. |
| Pricing* | Community free (BUSL); HCP by quote | Metered per key version + operations |
| Free tier | Yes | No |
| Licence | BUSL-1.1 — not OSI-approved | — |
| Best for | Dynamic, short-lived credentials at scale | GCP workloads and hold-your-own-key rules |
Choose HashiCorp Vault for dynamic, short-lived credentials at scale. Choose Google Cloud KMS for gcp workloads and hold-your-own-key rules.
* Published list pricing (vendor pricing pages, August 2026).