In most cases, Local makes it easy to get your offline development environment running HTTPS by providing a one-click solution for trusting a site’s SSL certificate.

Occasionally, if that “trust” process doesn’t work, you’ll need to manually let your Mac know that it can trust the Local site’s certificate.

Step 1: Create the certificate with Local

The first thing to do is click the “Trust” button next to the “SSL” section of the “Site Overview” page.

Even if this isn’t working in terms of getting the site to load over HTTPS, clicking the button directs Local to generate a certificate with the correct information about this site and attempt to register the certificate with macOS.

Step 2: Keychain Access

In macOS, most secrets are stored in “Keychains.” This includes things like passwords, ssh keys, and importantly for us, SSL certificates.

Using the “Keychain Access” application that comes with macOS, we can search for the SSL certificate that Local created. Once found, you can manage all sorts of settings for that specific certificate.

In our case, we want to update the “When using this certificate” setting from “Use System default” to “Always Trust“. This means that for this certificate, for this site, macOS will always trust the connection and stop annoying you with warnings about the certificate.

Set 3: Verify the certificate is trusted

Now that the certificate is set to “Always Trust,” how can you verify that everything is working?

Open the site in a browser again and ensure that there is a ‘lock’ in the address bar. If the lock is missing, the first thing to check is if the address bar has https:// at the beginning of the domain.

Step 4: Update the URLs within the Database

Once you’ve got the Local site’s SSL certificate trusted with macOS, and have verified that the site can be successfully loaded over HTTPS, all that’s left to do is to update the urls within the Local site’s database!

You can use a plugin like Better Search Replace to search for the regular HTTP version of the url and replace it with the HTTPS version of the url.

Another option is to use WPCLI which comes bundled with Local. To do this, all you have to do is:

1. Right-click on the site in Local and select “Open Site Shell”
2. Within the terminal window that opens, use the wp search-replace command to update http:// to https://. Using the above site as an example, the command would look something like:

wp search-replace 'http://ssl-madness.local' 'https://ssl-madness.local'