WP-CLI for multi-language development

This week at Rocketgenius, I was working on some visual refinements in one of our Gravity Forms add-ons. Because our suite of plugins supports multiple languages, part of my ongoing education is learning all about the tools and processes required to build our products for international support.

I’m just getting back into the swing of things again with full-stack development, and this week was the first time in my career where I’ve styled front-end components with internationalization in mind. It’s been an eye-opener for me just how limiting the web can be without this extra attention to detail, and I’m eager to start looking at my personal projects with fresh eyes, figuring out how I can make them accessible to an even broader audience.

One major aspect of internationalization is to style your user interfaces so that they can be read both left-to-right, such as for Latin-based languages, as well as right-to-left, for languages such as Arabic, Hebrew, Pashto, and so on.

Naturally, WordPress has multi-language support, but if you don’t know other languages (and perhaps don’t have every aspect of the user interface memorized), it can be challenging to find your way to the language switcher, then to the part of the admin you want to test (and then back again!). Thankfully, WP-CLI has some helpful commands that can ease this transition for you. Let’s review them.

Installing Languages

First, you’ll need to make sure whichever language you want to use is installed in your site, plugin, or theme. WP-CLI has a top level command called wp language which, when you run it, will reveal sub-commands for core, plugin, and theme! Running wp language core --help will show you all the commands you can run on core. The --help flag, of course, will show you available subcommands for the other commands, too.

Initially, these commands are going to be most useful:

  • wp language core list shows you the list of available languages, their english name, native name, installation status, the last update date, and whether an update is available.
  • wp language core install <language> will install one of the languages for you, where language is the identifier for a particular language. For instance, if I wanted to install Arabic, I would run wp language core install ar.

I encourage you to give these commands a try, and also explore the rest of the CLI commands available to you to see how you can work with languages you have already installed.

Switching Languages

Once you have a language installed, you can easily switch between them using a different CLI command: wp site switch-language <language>, where language is once again the identifier from the list command I mentioned previously.

Thus, if you installed Arabic in the previous step, you can run wp site switch-language ar, and WP-CLI will set the language of your WordPress site to load in Arabic instead. Simply refresh your browser page!

Styling Components

If your admin screen contains components with your own custom markup, and you haven’t considered right-to-left languages for your styles before, you might be surprised at the appearance of those components on the screen. In particular, directional margins and padding will be waaay off, because your properties were written with a left-to-right presentation in mind.

Thankfully, WordPress knows at the time you’ve activated a right-to-left language that it needs to provide you with the tools you need to style these components according. The html element includes a dir attribute when languages are read from right-to-left. Thus, any adjustments you need to make can be done by nested your element selectors in an html[dir="rtl"] selector.

To avoid needing to write lots of additional overwrite rules for the right-to-left counterparts, I prefer wrapping directional-specific properties in an html:not([dir="rtl"]) property. Here’s an example:

html:not([dir="rtl"]) .sidebar {
    margin-left: 1rem;

html[dir="rtl"] .sidebar {
    margin-right: 1rem;

Were I not to include the the wrapper for the left-to-right rule, I’d need to override the value of margin-left in the right-to-left selector. If you have lots of directional values, that can quickly add up.

Bash Aliases

Once you have a single right-to-left language installed, you can make it even easier to switch between your preferred left-to-right and right-to-left languages. Create a couple of Bash aliases, and reload your terminal!

alias ltr="wp site switch-language en_US"
alias rtl="wp site switch-language ar"

Then, when you need to switch between directional language types, it’s as easy as typing ltr or rtl in the command line. Nice!


Multi-language development opens up a whole realm of possibilities for your website. Paying attention to the UX presentation, in addition to providing text translation (naturally, not covered by this article), makes your content available to a much wider audience. Hopefully this small collection of commands will give you the extra encouragement you need to keep internationalization in mind when you work on your next project.