The get_previous_posts_link() WordPress PHP function retrieves the previous posts page link.
Usage
get_previous_posts_link($label);
Example:
echo get_previous_posts_link('Prev');
Parameters
- $label (string) – Optional. Previous page link text. Default: null
 
More information
See WordPress Developer Resources: get_previous_posts_link()
Examples
Basic Usage
Display the previous posts page link with default text:
if (get_previous_posts_link()) {
    echo get_previous_posts_link();
}
Custom Label
Display the previous posts page link with custom text:
if (get_previous_posts_link()) {
    echo get_previous_posts_link('Go to previous page');
}
Styling the Link
Add a CSS class to style the previous posts page link:
if (get_previous_posts_link()) {
    echo '<div class="nav-previous">';
    echo get_previous_posts_link('Previous Page');
    echo '</div>';
}
Combine with Next Posts Link
Display both the previous and next posts page links:
if (get_previous_posts_link() || get_next_posts_link()) {
    echo '<nav class="pagination">';
    if (get_previous_posts_link()) {
        echo get_previous_posts_link('Prev');
    }
    if (get_next_posts_link()) {
        echo get_next_posts_link('Next');
    }
    echo '</nav>';
}
Remove Trailing Slashes
Remove trailing slashes from generated links if you are using no-end-trailing slashes for your URLs. Add the following filter in your functions file:
add_filter('get_pagenum_link', 'user_trailingslashit');