WordPress themes simplify the website-building process by allowing you to choose a template with functionalities, and a visual style suitable for the site you want to create.
Each theme contains the WordPress functions file that allows you to customize and introduce new features.
This file lets you control all the website’s elements, from the layout of the admin panel to the background color on each page to the implementation of additional safety features.
Even the slightest change in the file’s code can cause errors such as the WordPress White Screen of Death, which is why you should edit it only if you’re confident in your coding skills.
In this article, we’ll show you 15 highly beneficial tips for optimizing the WordPress functions file to help you expand your website’s functionalities.
What is the Functions.php File?
A functions.php file is a part of the WordPress core or the group of files a website needs to work normally. All WordPress themes contain this file, and you can customize them by adding PHP code snippets to the file.
Moreover, the changes you introduce through this file can affect the entire website, not just the theme you’re currently using, enabling you to control your site’s behavior.
The scope of modifications you can add to a WordPress website through the functions.php file is limitless, as you can make a minor adjustment like defining how long you want the post excerpts to be, or using it to white label the admin panel.
Still, using WordPress functions and PHP plugins like WPCode or Functionality to insert code snippets into the file enables you to add code without editing it directly.
As a result, the functionalities you introduce to your site won’t be overwritten after you update the theme.
Accessing the Functions.php File
You can find the functions.php file in your theme’s wp-content folder, and you can access it from a website’s dashboard, through a web hosting account, or with an FTP client.
Here’s how to access the functions.php file from your site’s dashboard. Go to the Appearance menu on the site’s admin panel.
Choose the Theme File Editor option and click functions.php under Theme Files.
You can insert code snippets into the functions.php file directly from the Theme File Editor, and save them by clicking on the Update File at the bottom of the screen.
Alternatively, you can access the WordPress core files from your web hosting account. Go to the hosting platform’s dashboard, scroll down to the Files folder, and click the File Manager option.
Double-click on the folder containing your domain name to access its files, then open the public_html folder. Locate the wp_content folder, then enter the theme folder, and open the folder with the same name as the theme you’re using.
Scroll down through the theme files until you reach the functions.php file, and click on it.
The file will open in a separate window where you can insert code snippets.
Theme developers who want to download the functions.php file to their computers, and edit it with a desktop-based code editor can connect their hosting accounts with an FTP client like FileZilla.
You can navigate to the wp_content folder after you connect FileZilla to your domain. Locate the functions.php file in the theme’s folder, and choose the View/Edit option from the right-click menu.
Once you insert a code snippet into the file, you should save it, and upload it to your theme folder. The modifications you made will become visible on the website as soon as you upload the file.
Taking Safety Precautions Before Editing the Functions File
Each line of the code you add to the functions file must be accurate because errors can cause the feature you want to introduce, and your entire website to malfunction.
That’s why it’s not advisable to edit the functions.php file before testing the code, and ensuring it works. Let’s go through the safety precautions you should take before adding code snippets to this WordPress file.
Back up the Website
Some web hosts don’t include daily backups in all subscription plans, so you must check for a recent website backup before editing the functions file.
A minor mistake in the code you inserted into this file can crash your website, and without a backup, you won’t be able to revert to the website’s earlier version.
Create a Child Theme
The changes you make to the functions file will be overwritten every time you update the parent theme. So, instead of editing this file in the parent theme, you should create a child theme and use its functions file to introduce changes to your website.
You don’t necessarily have to code a child theme, as you can use Child Theme Configurator, Child Theme Wizard, or some other free plugin to create a child theme.
Set Up a Staging Environment
The code snippets you add to the functions file don’t always behave as you want them to, so you shouldn’t test them on your website’s live version.
Most web hosts let you set up a staging site, an identical copy of your live website, located in a private sandbox where you can test the new functionalities you want to add to your site.
Such an environment lets you see if the code snippet contains errors, and requires further editing without the risk of crashing your site.
Use a WordPress Functions.php Plugin
Instead of inserting code snippets directly into the functions.php file, you can use a plugin to introduce custom functionalities to your website or theme you’re currently using.
One of the most notable benefits of WordPress functions.php plugins is that you can choose where and how often you want to run a code snippet. In addition, these plugins provide you with a neat editor that gives you a clear overview of each line of code you write.
Installing a plugin like Code Snippets might be useful if you frequently edit functions.php, content.html, style.css, or script.js files because it lets you save progress on the code you’re developing, upload code snippets, and decide when you want to activate the code.
Keeping the Functions.php File Organized
Aside from making it easier to add code to the functions.php file, plugins help keep the file organized.
Each snippet you create with Code Snippets or similar plugins has a title and description, ensuring you won’t have trouble remembering which functionality a certain piece of code adds to your website.
Tagging is also an option if you’re working with vast quantities of code, as it helps you group snippets based on the parameters you choose.
Alternatively, you can add comments directly to the functions.php file, but doing so can clutter the file, and make finding a specific line of code even more difficult.
15 Tips for Optimizing the WordPress Functions File
The only limiting factors you’ll face when approaching the functions file are your imagination and coding skill level.
We’ve shortlisted some of the most beneficial tips for optimizing this file to spark your creativity and inspire you to introduce new features to your WordPress site, so let’s take a look at them.
1. Add a Second Admin to Your Site
Having two admin accounts can be helpful even if you’re managing the site on your own because it will give you a way to access the dashboard if you get locked out of your account for whatever reason.
2. Specify When Posts Appear in the RSS Feed
Google doesn’t index your content immediately after you publish it. This gives bots time to scrape your content, and index it in Google before Google, affecting its position in the search results.
This happens because each blog or any other piece of content you create is automatically added to the RSS feed as soon as you click the Publish button.
The functions.php file helps you deal with this issue by specifying when new content should appear in the RSS feed and giving Google enough time to index it. Optionally, you can insert code to this file that disables the RSS feed.
3. Switch Off the Search Function
All WordPress websites have the search function by default. However, you may not need this option if you have a one-page website or post a limited amount of content.
Spambots can abuse the search function, or add it to the URL even if a website doesn’t have a search box. Adding a relatively simple code snippet to the functions.php file will disable the feature on the entire website, making it impossible for spam bots to abuse it.
4. Create a Widget-ready Area for a Theme
All WordPress themes can have one or more widget areas that you can use to introduce different features on your website. Still, you don’t have to change the theme you’re using just because it doesn’t have as many widget areas as you need.
Instead, you can optimize the functions.php file to add new widget areas to the theme. Inserting a code snippet into the file will only register a widget area, and you must edit the theme’s footer or sidebar file to activate it.
5. Design Custom Shortcodes
Code shortcuts are incredibly useful whenever you want to add dynamic content to a page. The only downside is that by default, WordPress has only six shortcodes.
Creating custom shortcodes with the functions.php file will enable you to use these shortcuts for more than just embedding videos or creating image galleries.
A custom shortcode can introduce a wide range of functionalities to a website, such as automatically updating the year in all the website’s content or adding a related posts section to a page.
Moreover, you can edit the functions.php file to include shortcodes in post titles.
6. Edit the Footer in the Admin Panel
Branding or white labeling a website’s backend and front end is equally important. The footer in the admin panel usually contains ‘Thank you for creating with WordPress’ or a similar message.
Inserting a simple code snippet into the functions.php file can remove or replace this message with the text that promotes your brand.
7. Set Revision Limits for Each Post Type
Every time you edit a post you’ve already published, its new version is saved in your site’s database. Hence, revising a post too many times can overload the database with outdated versions of that post.
You can set the maximum number of revisions per post type in the wp-config file, or optimize the WordPress functions file to select a different limit for each post type.
Adding a few lines of code to the functions.php file will enable you to control revisions and prevent them from slowing down your site.
8. Hide the WordPress Version Number
Revealing the WordPress version on your site’s frontend can make it vulnerable to malicious attacks. The WordPress version number gives hackers valuable information, and helps them choose the most efficient way to attack your site.
Luckily, concealing this number with the functions file is a straightforward task involving adding four lines of code. You’ll have to reinsert the code after each WordPress update if you add code directly to the parent theme’s functions.php file.
9. Create a Custom Avatar
Most WordPress admins use the Mystery Person gravatar, but WordPress also generates several avatars based on your email address.
Creating a custom avatar with the functions file or a code manager plugin takes only a few minutes and doesn’t require you to have advanced coding skills.
All you need to do is add a link containing an image you want to use as an avatar, and a few lines of code to the file. The custom avatar will appear in the Discussion window in the Settings menu if the code works properly.
10. Alter Explainer Messages on Failed Login Attempts
Although you cannot disable the explainer messages WordPress displays after a failed login attempt, you can modify them.
These messages show the visitor if a specific email address is registered on your website, creating a potential safety issue.
A code snippet in the functions.php file can alter this message so that WordPress doesn’t reveal the source of the error, and only displays a message like ‘Something is Wrong’ or ‘Login Credentials are Invalid.’
11. Extend the Length of Post Excerpts
All blog indexes in WordPress are 55 words long. Their purpose is to give the reader an idea of what a blog is about and spark curiosity to read the entire article.
You can add a code snippet to the functions.php if you want to shorten or extend the default blog index length. Although there are no restrictions regarding how long or short a blog index should be, keeping this value under a 100 words is advisable.
12. Improve a Theme’s Pagination
Smooth and intuitive navigation throughout your WordPress website is vital for the quality of the experience your visitors will have while browsing your website.
Some themes only have rudimentary pagination that prevents you from organizing your content efficiently by distributing them over multiple pages.
Code snippets you add to the theme’s functions file enable you to improve pagination, or introduce a custom pagination system.
13. Control How Many Search Results Appear on Different Archive Pages
Setting the maximum number of posts that can appear in the search results is easy. You just have to go to the Settings menu on your site’s dashboard, open the Reading tab, and insert the desired value in the ‘Blog pages show at most.’
The only downside is that this option doesn’t allow you to set a different number of search results on different archive pages.
Optimizing the WordPress functions file will enable you to control how many search results appear on a particular archive page by adding only a few lines of code to it.
14. Randomize Background Colors
Creating a unique experience for each of your website’s visitors can be difficult because most themes have a limited range of background color settings.
You must edit the functions.php and header.php files, if you’d like to randomize background colors after a visitor lands on a page or refreshes it. Even though the code for this function isn’t complex, it’s advisable to test it in a safe environment before adding it to a live website.
15. Adjust the JPEG Optimization Quality
The images WordPress uses as thumbnails are automatically compressed, and their quality level is reduced to 82% of their original size. Automatic image compression can sometimes affect the image quality to the degree that its contents become unrecognizable.
Adding a single line of code in the functions.php file lets you control the thumbnail image quality. Moreover, you can use this code to disable compression by setting the default quality level to 100.
Using the Functions File to Improve Your WordPress Website’s Performance
Learning to edit your theme’s functions file will open a sea of customization opportunities, and enable you to make cosmetic and structural modifications to your website.
Creating an environment that will allow you to safely test and introduce the features you want to add to your website is paramount before adding code to this file.
Hopefully, some tips for optimizing the WordPress functions file we mentioned in this article will help you create a website that will attract a high volume of daily visitors.
Take a look at our guide to the best approaches to building a WordPress website if you’re unsure which way of creating a website on this platform works best for you.
