One of the best ways to improve the front-end functionality of your website is to add custom JavaScript to WordPress. However, figuring out how to do this can be tricky, especially if you are used to working with the Customizer to insert custom CSS.
Fortunately, you can use different strategies depending on your level of experience and what you are trying to achieve. After learning what your options are, you will be able to choose the solution for adding custom JavaScript to WordPress that makes the most sense for you.
In this post, we’ll walk you through three methods you can use to add custom JavaScript to your WordPress site, as well as discuss the pros and cons of each option.
Let’s get started.
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- Install a plugin like Head & Footer Code.
Pros and cons of using a plugin - Use your functions.php file
Pros and cons of editing your functions.php file - Add JavaScript to your header
Add JavaScript to your header using the wp_enqueue_script function.
Add custom JavaScript using the wp_head hook
Pros and cons of adding JavaScript to the header
Conclusion - Install a plugin like Head & Footer Code.
Using a plugin is one of the easiest ways to add JavaScript to WordPress. Head & Footer Code, for example, is a great tool:
This free plugin allows you to insert code in various ways. You can use it for Facebook Pixel , Google Analytics , custom CSS and more.
To get started, add the plugin to your site by navigating to Plugins → Add New from the admin dashboard, then search for “Head & Footer code.”
After clicking the Install Now and Activate buttons , you can locate the plugin settings by going to Tools → Head & Footer code . On this screen there are three boxes for the header, footer and body sections:
You can enter your custom WordPress JavaScript in one of these boxes. When finished, select the Save Changes button at the bottom of the screen. The code will then be loaded on every page of your site.
Pros and cons of using a plugin
The main advantage of using a plugin is that it is a beginner-friendly option. You don’t have to worry about editing your theme files . The Head & Footer Code plugin might also come in handy if you are looking for an easy way to add other types of code and custom CSS.
However, the disadvantage of this method is that it involves installing a third-party plugin, a solution that some site owners want to avoid. If you want to keep your plugins to a minimum, you might do better by using one of the other methods. Also, the plugin is designed for site-wide JavaScript changes rather than specific pages or posts.
- Use your own functions.php file.
Another method for adding custom WordPress JavaScript to your website is to take advantage of the built-in functions and hooks to modify the functions.php file . This approach involves manually uploading scripts to the server.
Before you begin, we recommend that you create a child theme . This step ensures that you will still be able to update the main theme safely. You should also make a backup of your site in case something goes wrong.
This method involves using the IS_PAGE function . You can add conditional logic to apply your custom JavaScript code to a single article or page.
To begin, locate and open your functions.php file , then copy and paste the following code snippet:
This code will add the JavaScript code to your header. To apply it to a single post, you can use the following:
Keep in mind that you will need to replace the number 3 in the example above with the ID number of the post to which you want to add the code. To locate that number, access the post from the admin dashboard, then click Edit . In the URL in the browser bar, the ID number is the number next to “post=”:
Save your file once you have replaced the ID number and add your custom JavaScript to the designated area. You can also repeat the same process for a single WordPress page.
Pros and cons of editing the functions.php file.
One advantage of editing the functions.php file is that you do not need to install another plugin. You can also use this technique to add features and functionality to both your theme and WordPress itself. This method can insert JavaScript into a single article or page or into all pages.
The only downside to this method is that it involves working with code and modifying files on your site. Therefore, it may not be the best option if you do not have experience in this department.
3.Add JavaScript to your header
Next, locate and open your functions.php file , then copy and paste the following code snippert:
Be sure to replace the template URL with your own. Finally, save your file.
Add custom JavaScript using the wp_head hook
You can also use the wp_head action hook to add custom JavaScript to your header via inline scripts. Again, this method is not preferable because it can create too many scripts. In any case, it is better than directly inserting scripts into the header.php file .
This method, which you can also use for the footer, uses action hooks to add inline scripts to your site. While wp_enqueue_script queues custom scripts, the wp_head approach prints scripts in the header template (and footer, if you use the wp_footer hook ).
To get started, go to the functions.php file , then copy and paste the following:
Note that the wp_head hook only activates on the front-end of your Web site. This means that any custom JavaScript you add using this method will not appear in the admin or login areas. However, if you want to add JavaScript to those areas, you can use the admin_head and login_head action hooks, respectively.
Pros and cons of adding JavaScript to the header
The wp_enqueue_script function is preferred by developers because it prevents conflicts that can arise with other options, such as directly adding scripts to the header.php . Also, using this method does not create dependent scripts.
The main problem with adding custom WordPress JavaScript to your site’s header is that it can cause problems with other plugins loading their own scripts. This configuration can also cause multiple scripts to load more than once, which can hinder the speed and overall performance of your website
Conclusion
By default, WordPress does not allow you to insert JavaScript code fsnippets into your pages and posts. Fortunately, with a few tricks you can add your own custom JavaScript without harming your WordPress website. The best method depends on your level of knowledge with editing your site’s files and where you want to apply the scripts.
As we have seen in this post, there are three ways to add custom JavaScript to your WordPress site:
1.Install a plugin like Head & Footer Code.
2.Use your functions.php file to add custom JavaScript to a single page or post.Add JavaScript for the header using the wp_enqueue_script function the wp_head hook.
3.Now that you know how to add custom JavaScript to WordPress, you may also be interested in our other guide on how to add custom CSS to WordPress.