Let's Encrypt vs step-ca
Let's Encrypt
letsencrypt.orgstep-ca
smallstep.comSide by side
| Figure | Let's Encrypt | step-ca |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | Yes | Yes |
| Web | Yes | — |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 3 | 3 |
| Spec score · Public Key Infrastructure Software | 8.6 (#3) | 8.2 (#7) |
| Integrations | Hosting providers can obtain and manage certificates for customers through their own ACME clients. | Documented integrations include Kubernetes cert-manager, Envoy SDS, ACME clients, OIDC providers, PKCS#11, Google Cloud KMS, AWS KMS and YubiKey PIV. |
| License | Boulder is open source under the Mozilla Public License 2.0. | The certificates repository is distributed under the Apache-2.0 license. |
| Rating on G2 | 4.8 out of 5 from 22 reviews. | 4.2 out of 5 from 10 reviews |
| Self-hosting | Boulder can be adapted to operate an internal, non-publicly-trusted ACME certificate authority, although its maintainers say it is often not the right production fit for organizations evaluating it. | Install options cover macOS Homebrew, Windows Winget or Scoop, multiple Linux distributions, Kubernetes Helm and Docker. |
| Support | Let’s Encrypt does not offer direct subscriber support and points users to its documentation and community support forums. | Open-source users are directed to community Discord support, with optional paid support contracts available from Smallstep. |
| What it does | Let's Encrypt is a free, automated, open certificate authority that provides TLS certificates for websites. | step-ca is an online certificate authority for automated X.509 and SSH certificate management. |
Plans
Let's Encrypt
- Let's Encrypt certificatesFree
- Let's Encrypt certificatesFree
- Short-lived certificatesFree
step-ca
- step-ca (open source)Free
- step-ca open sourceFree
- Smallstep PlatformPriced on request
In their own words
Let's Encrypt
Let’s Encrypt is a global Certificate Authority that provides SSL/TLS certificates for HTTPS connections. The ACME protocol verifies control of a domain, and compatible clients can automate issuance, management, and renewal. Its client directory includes Apache HTTP Server, Caddy, nginx, Kubernetes, Docker, and Windows/IIS environments. Certificates are Domain Validation only; Let’s Encrypt says it does not plan to issue Organization Validation or Extended Validation certificates. Wildcard certificates are available through the DNS-01 challenge. Standard certificates last 90 days, with an optional six-day lifetime; these periods cannot be adjusted. Subscribers generate and manage private keys on their own servers. Issued and revoked certificates are publicly recorded, and the service says its certificates are trusted by most browsers and operating systems. Certificates cost nothing. A registered domain can receive up to 50 certificates every seven days under published rate limits. Direct subscriber support is not offered.
step-ca
step-ca is an online Certificate Authority for automating X.509 and SSH certificate management. It issues X.509 certificates for TLS, mutual TLS, document signing and authentication, as well as SSH certificates for users and hosts. Provisioners can authorize issuance through ACME challenges, OIDC tokens, cloud instance identity documents and short-lived JWK tokens. Automated issuance and renewal are supported for clients, servers and Kubernetes workloads, alongside passive revocation. Templates can customize SANs or OIDs, restrict domains or key sizes, and create longer certificate chains. For CA signing-key protection, step-ca integrates with Google Cloud KMS, AWS KMS, Azure Key Vault, PKCS#11 HSMs, TPM 2.0 and YubiKey PIV. Its intended PKI design uses an offline root CA and a configured intermediate CA that issues end-entity certificates. Installation options include macOS, Windows, Linux, Kubernetes and Docker, and database choices include Badger, BoltDB, MySQL and PostgreSQL. The open-source plan costs nothing. Community help is available through Discord, with dedicated support contracts from Smallstep.