Choose Caddy if you want HTTPS handled for you: it gets and renews TLS certificates automatically for every site, even localhost, with a short Caddyfile or a JSON API. Choose Nginx if you want a long-established web server, reverse proxy, content cache and load balancer with fine-grained configuration. Caddy saves setup time; Nginx gives you more roles in one server.
I read Caddy's home page, documentation and automatic HTTPS guide, and nginx.org's home page, beginner's guide and licence. Here's how the two projects describe themselves.
Caddy and Nginx compared
| Caddy | Nginx | |
|---|---|---|
| Origins | Written in Go | Originally written by Igor Sysoev |
| HTTPS | Automatic by default, certificates obtained and renewed | Configured by you in the config file |
| Config | Caddyfile, or native JSON with a REST config API | nginx.conf configuration file |
| Roles | Web server and reverse proxy, built-in ACME server | Web server, reverse proxy, cache, load balancer, TCP/UDP and mail proxy |
| Licence | Free software, funded by sponsorships | 2-clause BSD License |
| Free option (as of October 2026) | Yes, free software | Yes, open source |
Caddy's big idea: HTTPS without thinking
Caddy's automatic HTTPS guide says it serves every site over HTTPS. For public domain names it obtains certificates from a public ACME certificate authority such as Let's Encrypt or ZeroSSL, keeps them renewed and redirects HTTP to HTTPS automatically. For localhost and internal IP addresses it uses its own local certificate authority, which it installs into your trust store, so even development sites run on HTTPS.
The requirements are the normal ones for any site: DNS records pointing to your server, ports 80 and 443 open and a writeable data directory. Caddy also offers On-Demand TLS, which gets certificates during the TLS handshake for customer-owned domains, the feature its home page says powers many white-label SaaS products. Several Caddy instances sharing storage coordinate certificate management as a fleet.
Nginx's strength: a proven all-rounder
nginx.org describes Nginx as an HTTP web server, reverse proxy, content cache, load balancer, TCP/UDP proxy server and mail proxy server, originally written by Igor Sysoev and distributed under the 2-clause BSD License. Its beginner's guide explains the architecture: one master process reads the configuration and manages worker processes, and the workers handle requests using an event-based model.
Everything is set in the configuration file, and you can reload it or even upgrade the executable without interrupting clients. Nginx also supports caching for FastCGI, uwsgi and SCGI back ends and has its own njs scripting language for more advanced logic.
Nginx's older rival is covered in our Nginx vs Apache comparison.
Config styles, side by side
This is where day-to-day life differs most. Caddy's docs say most people prefer to configure it with the Caddyfile, a human-friendly format, while its native config is a JSON document you can export and change through a RESTful API. Nginx uses its own directive-based configuration file, which gives precise control but means TLS certificates, redirects and renewals are yours to set up.
Traefik is another proxy that configures itself, and our Traefik vs Nginx guide compares it with Nginx.
Five questions to decide
- Want HTTPS working the moment a site goes live? Caddy does it by default.
- Running a SaaS where customers bring their own domains? Look at Caddy's On-Demand TLS.
- Need a load balancer, content cache or mail proxy as well as a web server? Nginx covers all of those.
- Is your team or host already standardised on Nginx configs? Stick with what people can support.
- Want to change config through an API? Caddy's JSON config API is built for that.
For the security basics around any web server, read my guide to securing and protecting your website, and if you run WordPress, my WordPress design and development guide for beginners is a good companion.
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My advice on Caddy or Nginx
For a small business site, a side project or an internal tool, Caddy is the quicker win: HTTPS is automatic and the Caddyfile is short enough to read in one go. For setups where you need load balancing, caching and proxying in one server, Nginx is the stronger fit because it does all of those jobs. If you already run Nginx happily, there's no need to switch just for automatic certificates.
Do you make web hosting or server tools? Tool makers can ask to be considered for a featured place in comparisons like this one.
Frequently asked questions
Does Caddy set up HTTPS automatically?
Yes. Caddy's docs say it serves all sites over HTTPS, obtaining and renewing certificates from public ACME authorities such as Let's Encrypt or ZeroSSL and redirecting HTTP to HTTPS.
What licence does Nginx use?
nginx.org says Nginx is distributed under the 2-clause BSD License.
What language is Caddy written in?
Caddy's documentation describes it as an extensible platform written in Go.
Can Nginx work as a load balancer?
Yes. nginx.org lists Nginx as an HTTP web server, reverse proxy, content cache, load balancer, TCP/UDP proxy server and mail proxy server.
How do you configure Caddy?
Most people use the Caddyfile, a human-friendly format. Caddy's native configuration is a JSON document you can manage through its REST API.
