{"id":18076,"date":"2026-09-18T04:50:53","date_gmt":"2026-09-18T10:50:53","guid":{"rendered":"https:\/\/www.supportpro.com\/blog\/?p=18076"},"modified":"2026-09-18T05:08:38","modified_gmt":"2026-09-18T11:08:38","slug":"how-caddys-automatic-https-works","status":"publish","type":"post","link":"https:\/\/www.supportpro.com\/blog\/how-caddys-automatic-https-works\/","title":{"rendered":"How Caddy’s Automatic HTTPS Works"},"content":{"rendered":"\n

When we open a website, we usually expect to see HTTPS<\/strong> in the browser address bar. HTTPS keeps the connection between the visitor and the website secure. It is especially important when a website handles login details, personal information, or other sensitive data.<\/p>\n\n\n\n

Setting up HTTPS manually can take some time. You need to get an SSL\/TLS certificate, configure the web server, and remember to renew the certificate before it expires.<\/p>\n\n\n\n

Caddy makes this process much easier with its automatic HTTPS feature.<\/strong><\/p>\n\n\n\n

What Is Automatic HTTPS?<\/strong><\/h2>\n\n\n\n

Automatic HTTPS is a feature in Caddy that can automatically set up HTTPS for a website.<\/p>\n\n\n\n

For example, suppose you have a domain called:<\/p>\n\n\n\n

example.com<\/p>\n\n\n\n

You can use a simple Caddy configuration such as:<\/p>\n\n\n\n

example.com {<\/p>\n\n\n\n

    root * \/var\/www\/html<\/p>\n\n\n\n

    file_server<\/p>\n\n\n\n

}<\/p>\n\n\n\n

After Caddy starts, it can automatically request a TLS certificate for the domain. Once the certificate is available, Caddy uses it to provide HTTPS for the website.<\/p>\n\n\n\n

This means you do not normally have to manually create a certificate and add a large amount of configuration.<\/p>\n\n\n\n

How Does Caddy Get the Certificate?<\/strong><\/h2>\n\n\n\n

Caddy uses the ACME protocol<\/strong> to communicate with a certificate authority.<\/p>\n\n\n\n

A certificate authority, such as Let’s Encrypt, provides certificates after checking that you control the domain.<\/p>\n\n\n\n

The process is fairly simple:<\/p>\n\n\n\n

    \n
  1. Caddy sees a domain in its configuration.<\/li>\n\n\n\n
  2. It requests a certificate for that domain.<\/li>\n\n\n\n
  3. The certificate authority checks the domain.<\/li>\n\n\n\n
  4. Caddy completes the verification.<\/li>\n\n\n\n
  5. The certificate is issued.<\/li>\n\n\n\n
  6. Caddy starts serving the website over HTTPS.<\/li>\n<\/ol>\n\n\n\n

    The whole process happens automatically when the required conditions are met.<\/p>\n\n\n\n

    What Does Caddy Need for This to Work?<\/strong><\/h2>\n\n\n\n

    Automatic HTTPS is convenient, but the server still needs to be configured correctly.<\/p>\n\n\n\n

    The domain should point to the server where Caddy is running. The necessary ports should also be accessible.<\/p>\n\n\n\n

    For a normal website, port 80 and port 443<\/strong> are commonly involved.<\/p>\n\n\n\n

    If the domain does not point to the correct server or a firewall blocks the required traffic, Caddy may not be able to obtain the certificate.<\/p>\n\n\n\n

    What Happens to HTTP Requests?<\/strong><\/h2>\n\n\n\n

    Caddy can also redirect visitors from HTTP to HTTPS.<\/p>\n\n\n\n

    For example, if someone enters:<\/p>\n\n\n\n

    http:\/\/example.com<\/p>\n\n\n\n

    Caddy can redirect the visitor to:<\/p>\n\n\n\n

    https:\/\/example.com<\/a><\/p>\n\n\n\n

    The visitor can then access the secure version of the website.<\/p>\n\n\n\n

    This is useful because some people may still type the website address without https:\/\/.<\/p>\n\n\n\n

    Does Caddy Renew the Certificate?<\/strong><\/h2>\n\n\n\n

    Yes. This is another useful part of automatic HTTPS.<\/p>\n\n\n\n

    TLS certificates have an expiration date. If you manage certificates manually, you need to remember when they expire and renew them.<\/p>\n\n\n\n

    Caddy takes care of the renewal process automatically.<\/p>\n\n\n\n

    This can save a lot of time, especially when one server is hosting multiple websites. Instead of checking every certificate yourself, Caddy handles the renewal in the background.<\/p>\n\n\n\n

    What If Automatic HTTPS Does Not Work?<\/strong><\/h2>\n\n\n\n

    Sometimes Caddy cannot obtain a certificate. This does not necessarily mean there is a problem with Caddy itself.<\/p>\n\n\n\n

    A few common things to check are:<\/p>\n\n\n\n