Caddy vs NGINX: Comparing Automatic HTTPS and Raw Performance

Caddy's standout feature is automatic HTTPS - it requests and renews certificates from Let's Encrypt or ZeroSSL by default the moment it starts serving a domain, with no separate Certbot process or renewal cron job to maintain. That single feature removes an entire category of manual SSL upkeep that trips up first-time server administrators.

NGINX doesn't provision certificates itself; it serves whatever certificate files you point it at, which typically means running Certbot or a similar ACME client alongside it and setting up a renewal schedule. That's a well-documented, reliable pattern used across most of the web, but it's an extra moving part Caddy simply doesn't require.

NGINX has spent close to two decades as one of the internet's most widely deployed web servers, with an event-driven architecture built specifically to handle very high concurrent connections using comparatively little memory, backed by years of production tuning at some of the largest sites online.

Caddy, written in Go, performs well for most small-to-mid traffic sites and has closed much of the historical performance gap, but NGINX's longer track record and deeper tuning options still make it the more common choice for high-concurrency production environments where every millisecond and every megabyte of memory is being optimized.