WordPress Plugin vs function.php File: Are They Same or Different?

A favorite subject indeed that is frequently uttered in the world of WordPressers— WordPress Plugin vs function.php or WordPress Plugin and function.php. Which one is better? which method is most reliable and user-friendly?

This must sound thrilling to the beginner WordPress users but this is the truth. The WordPress Plugin and function.php are the same.

Speaking in detail, every code snippet added in function.php file of WordPress Theme are actually the WordPress plugin we usually prefer to use for performing definite function of WordPress.

For details of WordPress plugin, check-out-

What can function.php file do can be done more conveniently and easily by the help of a plugin. But if you’re a serious blogger on WordPress platform, difference between these two must matter. And this knowledge must help you get most out of both WordPress Plugin and function.php.

WordPress plugin and function.php file

Here in this article all obscurity regarding the subject WordPress Plugin and function.php has been clarified for your happy understanding focusing the following topics—

  • WordPress Plugin vs function.php
  • Where WordPress Plugin and function.php files do exist
  • Pros and Cons of WordPress Plugin and function.php
  • Difference and similarity between these
  • Why to use function.php file
  • How to use custom code risk-freely
  • Which method to choose

Pre-words on WordPress Plugin and function.php file

Total WordPress works on three layers- WordPress Core files, Theme and Plugin. WordPress Core Files are similar to backbone of WordPress which builds the foundation to sustain the overall structure on. Themes are like skin on it. Theme furnishes WordPress site with physical Interfaces and structures it with Menu, Header, Footer, Sidebar, Post, Page and other elements.  Plugins add different functionalities to it.

Some functions Plugins can do among numerous probabilities are—

  • Adding Social Media Button
  • Adding Share Button
  • Image optimization
  • Including SEO tool
  • Adding Subscription Form
  • Turning WordPress a woo-commerce or other sites
  • Adding Quiz Editor
  • Including Backup tool and so on

But these functions were supposed to be performed by bunches of codes inserted into function.php file of any WordPress theme.

And such was done in pre-plugin period of WordPress. At its inception on May 27, 2003, WordPress had no plugin. Plugin System came into scenario on May 22, 2004 after third release of WordPress Mingus (v1.2) by name.

Until this release, users had to extend WordPress with specific features by using HACKS, a set of bundled files usable in function.php file. They created Hacks by themselves or got it done by skilled coders.

After 2004, Plugin appeared in the WordPress world carrying unlimited probabilities to both experts and non-techy users to extend and upgrade WordPress most possible ways.

Where do WordPress Plugins and function.php file reside?

The function.php file is a Theme file written with php code. When you first install WordPress, you find a simple default theme which you can replace anytime with a free or paid one.


public_html→wp-content→ Plugin


wp-content folder→ Theme subfolder→ Definite theme folder→ function.php file

Theme files are basically php and css files that are written in order to structure, design and format WordPress Post, Page, Header, Footer etc. Among the files, function.php file is used to add different functionality and features to WordPress. Each function is actually a bundle of php codes that are embedded in function.php. You can add as many function as you need in this file. Noted, function files are theme specific. When you switch Theme, functions go off.

You can get to function.php file from here:

wp-content folderTheme subfolderDefinite theme folderfunction.php file

or Appearance (Admin Panel)→ Editor→ (Theme files) function.php

On the other hand, plugin can do the same as function’s code bundle can. When you install a plugin, it is stored in wp-contentPlugin subdirectory of WordPress installation. If you have coding expertise, you can edit Plugins from WordPress DashboardPluginsEditor or from Cpanel via FTP Channel.

Pros and cons of Plugins

The history of Plugin shows that it evolved as a historic necessity for placing function code in a separate directory so that non-technical users can handle it without entering into coding complication and can avoid mistake. But there are some WordPress users who dislike to clutter their site with too many plugins. However here are the pros and cons of using plugin in place of function code—

  • Plugin is not theme-dependent; so users won’t lose it if theme is switched.
  • No need to enter the complication of editing core file.
  • Any user coder or non-coder can use.
  • easy to edit, update, disable, delete or reinstall.
  • Easy to manage as many plugin as one needs.
  • No risk to handle
  • Selection of appropriate plugin is a matter. Plugin may lower down site’s performance if it is not well-coded or well-selected.
  • Plugin needs regular update. Unupdated plugin may malfunction with the latest version of WordPress.
  • The Developer may stop plugin functioning. Consequently you can lose valuable works around plugin.
  • Security threat.

Pros and cons of funcion.php file

In contrast with Plugin, function.php file also has merits and demerits as are shown below—

  • You can store all of your code in a single file which is easy to handle.
  • Working with function.php file may be your practice ground to attain coding skill
  • Less security threat
  • Less possibility to lose your work relating a code snippet.


  • As it is theme dependent, you can lose your work and customization if theme is switched.
  • Complicated to edit a code snippet among many others
  • Very risky to handle with custom code by the unskilled users. A slight-mistake may cause great ruin to entire site.
  • If a child theme is not used, updating theme will overwrite function.php file.
  • In case of some functionality, additional script and style (e.g. css file) may be essential beyond php file.

Is there no difference between WordPress Plugin and function.php

As we mentioned above, plugin was invented aiming to upgrade extensional capacity and usability of WordPress to the common users which created a new age in WordPress World. Reasonably function.php file is never an Equal to WordPress plugin though they serve the same purpose. You cannot add all functionality and features in a function.php file. In some cases, you may have to add additional script and style to make a function work. Also there are other scenario where it is more convenient for you to use function code. Developers agree that function code snippet can be used in case of small functions such as adding Google Analytics to WordPress Dashboard, Display word number of an article etc.

WordPress plugin and function.php sample

Why to use function.php

From our illustration, it is clear that function.php has limitations why it cannot win over Plugin. However followings are the situations when you might consider it appropriate to use php code snippet to avoid plugin hassle—

  • If the function is small and less important
  • If the code snippet is simple.
  • If proper plugin is unavailable for a specific function you’re looking for
  • If the functionality is directly related to your Theme or Child Theme such as showing dates or author’s name, image structure resetting etc.
  • If you’re a php developer and feel ease with coding activities.

However here are a number of functionalities in which cases, you can add custom code snippet in Function.php file. There are also websites where you can download or copy such snippets from free of cost

  1. Adding author profile field
  2. Dynamic copyright date in Footer
  3. Adding Google Analytics stat to WordPress Dashboard
  4. Adding estimated reading time to posts
  5. Changing Footer text
  6. Adding featured image in RSS feed
  7. Disabling RSS feed etc.

Risk-free way to insert function

As time passes by, technology goes on and on. If it is the fact that you frequently use custom codes for your site, there is also plugin by which you can manage, edit and organize your codes more efficiently and risk-freely out of function.php file in theme independent mode. Such plugins are Site Specific WordPress Plugin and Code Snippet plugin. You can consider using them.

Bottom Line

No doubt, you’ve gotten all clarified. Now this question is irrelevant which method you should use. Probably, You have already made up your mind in which fields you’re going to use Plugin and where custom codes.

Contextually share with us your valued experience of using plugin or custom code snippet by commenting. Also share this article to your WordPresser friends if you consider it really helpful.

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