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WordPress Plugin VS functions.php File

WordPress Plugin VS functions.php File

This article answers the question “which is better between WordPress plugin vs functions.php file?” with a list of their pros and cons. This is a common question we have received from many readers. Later on, those who are faced with the same question can directly find a professional answer from this article.

It is often be misunderstood that adding code snippet to functions.php files is always better than installing a WordPress plugin. But there are some instances where you should install a plugin. In fact, both have their own pros and cons. The solution you are going to use should be according to the specific situations.

WordPress Plugins VS functions.php File

Two solutions are often used to extend the functionality of WordPress: via plugins or via code in functions.php file. Different roads will lead to the same goal. And everything goes well with either of them. But which one is better for WordPress performance catches the attention of most readers.

What comes after installing too many plugins are often the worries of slow speed and low WordPress security. With the use of code, there is also a worry to mess up a WordPress site but have no ability to fix the errors.

Discussed in the following is the detailed comparison between WordPress plugin vs functions.php file. It can be learned from our further discussions which is better for your WordPress site.

Pros and Cons of functions.php File

Developers are more willing to edit functions.php file, which enables them to add any custom functionality for their own theme. In most cases, however, a WordPress plugin features a fixed functionality.

WordPress Plugin VS functions.php File - functions.php


  • In admin area lies a built-in theme editor with which you edit functions.php file easily.
  • In one file, all code snippets can be copied and pasted.
  • Constant coding practices will increase your knowledge of how code works.


  • What you have done to theme’s functions.php file will fail to work when you use a new theme or update your old one.
  • A child theme is required for your WordPress before making changes to your theme.
  • With the passage of time, you will have more trouble telling them code and custom code apart.
  • Additional scripts and stylesheets are necessary for some code snippets to work properly.

It is a fact that many tricks are available for you to edit functions.php file. But code snippets cannot apply to all cases when there are proper WordPress plugins. With the same code, functions.php file and the WordPress plugin will have an identical influence on performance.

And a great possibility exists that you cannot add new features and functionality to WordPress by editing the functions.php file. A custom code can be a typical example which might need additional scripts and styles. But functions.php file is better for developers to add theme based functionality.

Pros and Cons of WordPress Plugins

Theoretically speaking, plugins in WordPress work the same way as apps in your smartphone. With code contained, WordPress plugins will simplify your process to add new features and functionality. Chances are that beginners can build a powerful WordPress website with the help of them.

WordPress Plugin VS functions.php File - WordPress Plugins


  • Once your theme is changed, a WordPress plugin still works as usual.
  • With the same code, a plugin will have the same impact on performance as functions file does.
  • You are free to put a plugin in a certain state: activate, disable, reinstall, and more.
  • Under the guidance of the detailed description, the goal can be easier achieved with a plugin.


  • When the new updates come, you have the need to keep up with the changes.
  • Free plugins are easy to be abandoned in the future for some reasons.
  • Plugins will reduce the chances of practising your coding skills.

When to Use WordPress Plugins?

A plugin which comes with the same code is more recommended for WordPress.

On one hand, it will save you much time and energy to arrive at the same end. Things will be much easier when you are relying on a proper plugin in comparison with editing every single of line. Moreover, the plugin developers will probably fix the vulnerability, add more features, optimize the performance, and many more. Under this circumstance, there are many benefits brought by new updates. On the other hand, there is no difference on WordPress performance no matter where the code loads.

It is easy to found yourself stuck in the middle of sea, because there are thousands of plugins in the market. We would like to recommend some best WordPress plugins so that you can make quick and right choices.

When to Edit functions.php File?

When no plugin is available for you add the functionality you need, you can add simple code snippet to your theme’s file. And such is the case with the functionality which has a relationship with your child theme or WordPress theme, for example, showing today’s date.


Zoe is a freelance writer who has a deep knowledge about WordPress. She loves everything related to website building and loves to share her experience with people all over all the world. In the daily life, Zoe loves detective novels as it can train her logical thinking and creativity.