Founded in 2019, ZeroSSL is a modern certificate authority offering free DV SSL certificates with an intuitive web management interface, ACME protocol, and REST API — with over 5 million certificates issued, it's the most popular free SSL alternative to Let's Encrypt.
Let's Encrypt is the world's largest free, open certificate authority operated by ISRG, serving 300M+ active websites with 70%+ of global CA issuance. Uses the ACME protocol for fully automated 90-day DV TLS certificate lifecycle management.
SSL Mate (founded 2014) is a DevOps-focused SSL automation SaaS platform that leverages Certbot/ACME for end-to-end certificate lifecycle management across Sectigo, DigiCert, and Let's Encrypt — covering ordering, deployment, monitoring, and renewal.
Namecheap SSL is the SSL certificate product line resold by Namecheap (founded 2000, Phoenix AZ), the world's second-largest domain registrar, featuring Sectigo PositiveSSL from $5/yr, multi-brand CA options, and free reissuance — the top choice for budget-conscious SSL buyers.
Buypass SSL is the SSL certificate product line of the Buypass Group, offering free 180-day DV SSL certificates with ACME auto-renewal — the most popular free CA alternative to Let's Encrypt.
Recurly Payments is Recurly's subscription billing payment product, founded in 2009 in San Francisco. Covering 200+ countries and 40+ payment methods, its Smart Retry engine recovers 10%-30% of failed payments.
Buypass is a Norway-based Certificate Authority (founded 1968) offering free 180-day SSL certificates via ACME automation, alongside the Norwegian government e-ID system (Buypass ID) and eIDAS-qualified digital signatures.