The hidden costs of switching to Caddy in 2026

Caddy wins on simplicity but loses on throughput

I recommend Caddy for new small-team projects because it handles HTTPS automatically without extra configuration. Caddy 2.8 delivered 142,000 requests per second on 1KB static files during April 2026 benchmarks, surpassing Nginx 1.26’s 116,000 requests per second on 16-core ARM hardware. While Nginx maintains a 32.8% market share, Caddy holds approximately 1% of the market. I would not suggest Caddy for high-traffic streaming workloads, as Nginx pulls 17% ahead for files larger than 1 MB. Nginx uses a zero-copy path and tighter buffer management for these larger payloads. Caddy’s compiled binary is roughly 45 MB due to its Go runtime, while Nginx stays under 1 MB. Caddy uses 25 to 35 MB of RAM at idle, which is ten times the 2 to 3 MB Nginx consumes. While Nginx handles large-file streaming and complex rewrites through its event-driven, single-threaded-per-worker model, Caddy relies on Go goroutines to manage concurrency through lightweight green threads scheduled across operating-system threads to handle thousands of concurrent connections.

Automation errors trigger Let’s Encrypt limits

Teams migrating from Nginx often hit Let’s Encrypt rate limits because Caddy automates certificate requests. One user upgrading to Caddy v2.8.x encountered an error where the server attempted to register a new account for every certificate request, hitting the limit of 10 accounts per 3 hours per IP. Let’s Encrypt also restricts issuance to 50 certificates per registered domain every 7 days and 5 certificates per exact set of identifiers every 7 days. I would avoid using Caddy for massive certificate bursts without careful planning. A single configuration error during a deployment can block your access to HTTPS for up to a week depending on the rate limit you hit.

The Let’s Encrypt API uses a token bucket algorithm to calculate these limits per request. You can use the staging environment to test your client and avoid these production blocks. For users of the DNS-01 challenge, typos or missed steps in the DNS zone configuration cause validation failures. I would skip the temptation to bypass these limits by repeatedly reinstalling your client, as this action consumes resources and hits limits faster. Organizations must also respect the limit of 300 new orders per account every 3 hours to avoid interruptions.

Configuration differences and deployment friction

Configuration workflows differ significantly between these tools. Caddy uses a short, outcome-based Caddyfile, while Nginx requires explicit directives for headers and proxy settings. Since you already know how to manage a config file, you should notice that an Nginx configuration for a reverse proxy requires manual settings for Host, X-Real-IP, and X-Forwarded-For headers to match the simplicity of a single Caddy line. I noticed that Caddy users running in Docker containers often face port conflicts when trying to expose multiple services. For instance, one user running Baserow and n8n in Docker had to run Caddy on port 443 while the other service used port 4443 to avoid collisions. Users also find that On-demand TLS with multiple wildcards causes Caddy to fall back to a local issuer instead of Let’s Encrypt. If you move from Caddy to Traefik, you might struggle to replicate Caddy’s conditional scripting with middlewares or the ability to mix and match declarations between files and Docker labels. How does a team manage certificate renewal if the issuer configuration changes between reloads?

I recommend Caddy when you prioritize developer experience and reduced maintenance. You should choose Nginx if you have an established infrastructure with existing Nginx templates and automation. I would skip the migration if your team relies on highly detailed caching or specific header behavior that Nginx manages more explicitly.