How to Transfer an Existing Theme Design

and the internet is decidedly unhelpful.

When this happens to me, it’s usually because I’m not asking the “internet” the right question (ie not using the right search phrase). Sometimes we simply don’t know what we don’t know… to even know the appropriate terms to put in the search engine.

And that seems to be the case here.

In this case, appropriate phrases like “export block theme”, “export FSE theme”, “export Twenty Twenty-Three theme”, etc all turn up a ton of helpful results.

I tried to just download the twentytwentythree theme folder and upload it to the other site, but none of the layout/design elements transferred over.

Block theme customizations are stored in the database (after all, they use the same block editor used for publishing posts/pages), so grabbing the theme’s folder from the file system will only give you the original theme and none of your customizations.

But you can export a .zip file with the customized version of the theme from Site Editor (APPEARANCE => EDITOR, and click anywhere in the site preview to open the editor), as shown in the screenshot below.

You’ll then have to upload the downloaded .zip file to the new site, exactly the same way as you upload any custom theme to WordPress.

Good luck!

I’m afraid that isn’t the answer. The .zip file it downloaded only contained the theme files, not any of the customizations.

Every article I found on importing/exporting the customized settings said I had to install a plugin. Is that the only option?

I’ve just tested the procedure I explained above: and it works. I’ve embedded a screen recording below.

If it’s not working for you,

1) You may be doing it wrong, or

2) Something in your WordPress installation is making it not work.

Every article I found on importing/exporting the customized settings said I had to install a plugin.

You’re getting articles based on what you’re searching for. Garbage in, garbage out. I’ve already explained this in my earlier post. I even gave appropriate search phrases to get appropriate results specifically for BLOCK/FSE themes.

That worked on a site that had no prior alterations to the theme, but when I uploaded it to a site that I’d already been tinkering with, the old elements were still there and nothing changed. I’m trying to test a design before installing it on my main site since it seems that WordPress is not designed to test themes before activating them.

You may try with “WP Migration Tool” which clones a site and pushes it into another site without any hassle.

Not sure anyone is reading this any more, but I’ve had the same problem as the OP, and there seems to be a shortcoming in the way WordPress handles exports of customisations in themes.

The problem: how to customise a block theme on a website on one server (e.g. a dev server) then copy/replicate the customisation to another server (e.g. the live server) with the same theme and same/similar website.

I can’t see any way to do that except to write down all the cusomisation, and enter it by hand on the second server.

I could export the customised site as @gappiah suggested in post 2, but that creates problems. When you customise a site with the site editor, it doesn’t change the theme in (e.g.) …/wp-content/themes/twentytwentyfour/, that stays “pure”. Rather, it stores the customisation in the database (mainly in wp-options, I think).

E.g. if you customise the header (using the site editor), the file header.html in the theme is not altered, the change is stored in the database. But when you export as per @gappiah, the exported zip contains a modified theme with a modified header.html. If you load that on another site you haven’t replicated the first site, that is with a “pure” theme plus database changes. Instead you have an altered theme. Thus if the theme is updated subsequently, it will overwrite your customisations.

What am I missing?

What I was missing appeared to be the plugin “FSE Theme Design Import/Export“. This exports block theme customisations from the database to an xml file, and then this can be imported to another site using the same theme.

A quick tests suggests it does the job. It saves templates, template parts and styles that have been customised. Not sure if it saves patterns and I don’t think it saves navigation menus.