acme.sh vs AWS Certificate Manager

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.

AWS Certificate Manager (ACM) provisions, manages and deploys public and private SSL/TLS certificates for AWS, hybrid and multicloud workloads. Certificates may cover one domain, multiple named domains, wildcard domains or combinations. Management is available through the AWS Management Console, AWS CLI and ACM APIs, with usage auditable in AWS CloudTrail logs. Amazon-issued certificates can renew automatically when DNS validation is used; otherwise ACM sends notices as expiration approaches. Public-certificate integrations include Elastic Load Balancing, Amazon CloudFront, Amazon API Gateway, AWS Elastic Beanstalk and AWS CloudFormation. AWS Key Management Service helps protect stored private keys. Customers can import third-party CA certificates and deploy them with Elastic Load Balancers, CloudFront and API Gateway; importing costs nothing. The default quota is 10 domain names per certificate, with requests up to 100. The integrated-services public-certificate plan is free and non-exportable. ACM is available on web and API platforms.