acme.sh vs Certify The Web

acme.sh is a free Unix shell ACME client for automating SSL/TLS certificate issuance, renewal, and installation. Its installer creates a daily cron job to check certificates and renew them when needed. Written purely in shell, it is compatible with Bash, dash, and sh; the README says general use needs neither Python nor root or sudo access. It supports ECDSA, RSA, SAN, and wildcard certificates, with validation modes including webroot, standalone, standalone TLS-ALPN, Apache, Nginx, DNS, DNS alias, stateless, and DNS persist. ZeroSSL is the default certificate authority. Listed alternatives include Let's Encrypt, SSL.com, Google Public CA, Actalis, Pebble strict mode, and any RFC8555-compliant CA. The project says API integrations cover most DNS providers. Renewal uses a CA’s ACME Renewal Information when available, with a 30-day fallback rule otherwise. Manual DNS mode cannot renew automatically because each renewal requires a new TXT record to be added by hand. Tested systems listed include macOS, Windows through Cygwin, FreeBSD, and multiple Linux distributions. The project is GPLv3 licensed and officially maintained by ZeroSSL; release tags from version 3.1.6 onward are signed with the maintainer’s SSH key, while earlier tags are unsigned.

Certify The Web provides products for requesting, deploying, and renewing TLS certificates. Certificate Manager is intended for Windows servers or desktops, Management Agent for headless Linux and macOS systems, and Management Hub for central administration of multiple instances. The tools support ACME authorities including Let's Encrypt, Google Trust Services, ZeroSSL, Actalis, and private or enterprise CAs. Domain checks can use HTTP or DNS, with options ranging from built-in providers and Certify DNS to manual TXT records or custom scripts. Deployment tasks cover IIS, Apache, nginx, Tomcat, Exchange, ADFS, RDP, Azure App Service, Azure Key Vault, HashiCorp Vault, and IIS Centralized Certificate Store. Other deployments can use scripts, webhooks, SSH/SFTP, or UNC shares. Hub offers a web interface, API, role-based access, managed DNS challenges, and certificate monitoring across instances. A free evaluation has no feature limits or time limit. Cloud-managed licensing starts at $4.99 a month per install; other plans have annual or longer billing terms. Licenses do not bypass certificate authority rate limits.