27. Image SEO | SEO Forge - Rank Higher with AI-Powered SEO

Automatic alt text generation and filename cleanup on image upload. These features help improve image accessibility and SEO without manual effort. PRO feature.

Filename Cleanup Algorithm

Applied via the sanitize_file_name filter, this cleans up messy filenames before the file is saved to the uploads directory:

Extract filename without extension
Convert to lowercase
Replace _ and spaces with -
Remove all non-alphanumeric characters (except -)
Collapse multiple consecutive dashes into one
Trim leading/trailing dashes

Upload Filename	Cleaned Filename
`My Photo (1).JPG`	`my-photo-1.jpg`
`IMG_20240115_final.png`	`img-20240115-final.png`
`Screenshot 2024.png`	`screenshot-2024.png`
`DSC__0042---edit.jpeg`	`dsc-0042-edit.jpeg`
`product photo v2 FINAL.webp`	`product-photo-v2-final.webp`

Auto Alt Text Generation

On add_attachment hook, if the image has no alt text, SEO Forge generates one from the filename:

Take the filename (without extension)
Remove dimension suffixes (e.g. -800x600)
Remove common suffixes (scaled, rotated, cropped, edited, copy, final, v1)
Replace - _ . with spaces
Apply MB_CASE_TITLE capitalization (Title Case)
If the image has a parent post, append - {parent title}

// Manually generate alt text for an existing image
$attachment_id = 123;
$filename = pathinfo( get_attached_file( $attachment_id ), PATHINFO_FILENAME );
$alt = str_replace( [ '-', '_', '.' ], ' ', $filename );
$alt = mb_convert_case( trim( preg_replace( '/s+/', ' ', $alt ) ), MB_CASE_TITLE );

$parent_id = wp_get_post_parent_id( $attachment_id );
if ( $parent_id ) {
    $alt .= ' - ' . get_the_title( $parent_id );
}

update_post_meta( $attachment_id, '_wp_attachment_image_alt', sanitize_text_field( $alt ) );

// Bulk-generate alt text for all images missing it
$images = get_posts( [
    'post_type'      => 'attachment',
    'post_mime_type' => 'image',
    'posts_per_page' => -1,
    'fields'         => 'ids',
    'meta_query'     => [ [ 'key' => '_wp_attachment_image_alt', 'compare' => 'NOT EXISTS' ] ],
] );

foreach ( $images as $img_id ) {
    $filename = pathinfo( get_attached_file( $img_id ), PATHINFO_FILENAME );
    $alt = str_replace( [ '-', '_', '.' ], ' ', $filename );
    $alt = mb_convert_case( trim( preg_replace( '/s+/', ' ', $alt ) ), MB_CASE_TITLE );

    $parent_id = wp_get_post_parent_id( $img_id );
    if ( $parent_id ) {
        $alt .= ' - ' . get_the_title( $parent_id );
    }

    update_post_meta( $img_id, '_wp_attachment_image_alt', sanitize_text_field( $alt ) );
}

Missing Alt Text Warning

In the Media Library edit screen, SEO Forge displays a warning for images without alt text via the attachment_fields_to_edit filter. This visual indicator reminds editors to add descriptive alt text for accessibility and SEO.

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