Function and usage of is_blog_installed() in wordpress


Answers ( 1 )


    The is_blog_installed() function in WordPress is used to determine if WordPress is already installed. Here's a detailed explanation:

    Function Signature

    is_blog_installed(): bool


    This function checks whether WordPress has been installed and properly set up. It primarily works by checking the status of the WordPress installation.


    1. Cache Checking: The function initially checks the cache for installation status. This is particularly relevant if you're using a caching plugin in WordPress, which can store these values. If the cache indicates that WordPress is installed, the function will return true.

      • Note on Default Cache: If you're using the default WordPress caching mechanism and the database becomes inaccessible for some reason, the function may not be able to accurately determine the installation status.
    2. Option Checking: Apart from cache checking, is_blog_installed() looks for the 'siteurl' option in the WordPress options table. The presence and proper configuration of this option are indicative of an installed and configured WordPress site.

    3. Theme Developer Handbook: For further understanding of this and similar theme functions, the WordPress Theme Developer Handbook, particularly the Conditional Tags article, is a recommended resource. This handbook provides comprehensive insights into various functions and their usage in theme development.

    Return Value

    • Type: bool
    • Description: The function returns a boolean (true or false). true indicates that WordPress is installed, while false suggests that it isn't.

    Sample Usage

    Here's a simple example of how is_blog_installed() might be used in a WordPress theme or plugin:

    if ( is_blog_installed() ) {
        echo "WordPress is installed!";
    } else {
        echo "WordPress is not installed!";

    In this example, the function checks if WordPress is installed. If it is, the script prints a message confirming the installation; otherwise, it indicates that WordPress isn't installed.


    The is_blog_installed() function is a straightforward yet powerful tool for theme and plugin developers to verify the installation status of WordPress. Its primary utility lies in scenarios where a theme or plugin needs to alter its behavior based on whether WordPress has been installed and configured.

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