In this tutorial, you will learn about a plug-in you can use to help you provide left-to-right support within a Javascript-based website. Providing multi-language support on a site used to be a challenge. Different languages can have different characters. A sentence in English might require double the amount of characters when it is translated into German. On top of that,, if you want to cater for languages like Hebrew or Arabic, you will need to provide right-to-left support.

I remember having to do this several years ago working on a monolithic C# e-commerce platform. The business gave the team a hard deadline to have an Arabic version of the site working within 3 months. The CSS was written a few years before and providing multi-language support was never part of the original scope. With such a tight-deadline the team did the only things possible... hack the code until it was deemed acceptable.

Luckily things are much better now than they were then. If you are using web-pack and PostCSS you can use a plug-in to take the pain away! PostCSS is a JavaScript package that can automate routine CSS operations. 'CSS operations' is pretty vague, if you want to learn more I have previously discussed some of its useful features here. You can probably guess where this is heading. There is a right-to-left PostCSS plug-in that will automatically switch your website to render text in a right-to-left format. This will all be done using an amazing package called postcss-rtl.

Using postcss-rtl

The command to install postcss-rtl with yarn/npm is shown below:

If you have a postcss.config.js file, you can enable the package like so:

With the package enabled, when the CSS is built, a right-to-left version will also be generated. postcss-rtl will invert each CSS style to work from left-to-right to right-to-left. With some simple configuration, your whole site can be converted quickly, saving your months worth of effort!

First, let us quickly discuss how to write right-to-left CSS. When you want to write CSS to target different text directions, you use the dir attribute on an element. The dir attribute sets the base direction of how text is displayed. To enabled right-to-left test on a page you would write this HTML:

There are several approaches on how you would write the CSS, some approaches may include:


Instead of manually having to go through the entire site and change everything, we can get postcss-rtl to do it for us. This is the overview of how this process will look. When your application compiles, it will call web pack. At some point, web-pack will call post-css to process the applications CSS and perform any additional tasks. If configured correctly, post-css will also run postcss-rtl. When postcss-rtl runs it will also auto-generate additional CSS targeting by automatically adding the 'dir' attribute. For example, take this simple selector:

After postcss-rtl runs, if you look within the applications CSS file you will find a new selector that includes 'rtl' and 'ltr':

Armed with these new styles, if you set your pages HTML dir to RTL and reload the page, you should now see that your site's text has flipped. A word of caution, postcss-rtl is a plug-in which means that it may not look perfect for all languages without any additional custom styling. It will, however, get you a lot further down the path without having to do much. From my experience, we probably saved 4 weeks of effort using this plug-in compared. Having manually go through and write all the CSS is a chore so let postcss-rtl do the grunt work for you. Happy coding!