PDF Thumbnail Generator

Generates thumbnail for PDF file automatically after file is uploaded to the Media library.

You can also generate thumbnails for old PDF files that are already in the Media library – you can generate missing thumbnails or regenerate all thumbnails.

Imagick library must be installed on your server, otherwise this plugin will not work

• automated test after plugin activation to make sure it will work on your server
• works with all types of WordPress installations: domain, subdomain, subdirectory, multisite/network
• works on Apache and NGiNX
• automatically generate thumbnail for new uploaded PDFs
• (re)generate thumbnails for existing PDFs in Media library
• set maximum width of PDF thumbnail
• set maximum height of PDF thumbnail
• set image quality of PDF thumbnail
• set image file type of PDF thumbnail

Shortcodes

pdf_thumbnail

Maybe you want to display PDF thumbnail by using a shortcode

[pdf_thumbnail id="123"]

pdf_thumbnail_url

Maybe you want to display PDF thumbnail url by using a shortcode

[pdf_thumbnail_url id="123"]

pdf_clickable_thumbnail

Maybe you want to display clickable PDF thumbnail that will open PDF in new tab

[pdf_clickable_thumbnail id="123"]

Functions

get_pdf_thumbnail_url

If you want to return PDF thumbnail URL you can use

get_pdf_thumbnail_url( $pdf_id )

it works similar to wp_get_attachment_url and it will return something like

https://site.com/wp-content/uploads/2022/01/example.pdf.png

get_pdf_thumbnail_path

If you want to return PDF thumbnail URL you can use

get_pdf_thumbnail_path( $pdf_id )

it works similar to get_attached_file and it will return something like

/www/site.com/wp-content/uploads/2022/01/example.pdf.png

get_pdf_thumbnail_image_src

If you want to return PDF thumbnail url, width and height you can use

get_pdf_thumbnail_image_src( $pdf_id )

it works similar to wp_get_attachment_image_src and it will return something like

[
    0 => 'https://site.com/wp-content/uploads/2022/01/example.pdf.png',
    1 => 600,
    2 => 800
]

get_pdf_thumbnail_image

If you want to return PDF thumbnail image tag you can use

get_pdf_thumbnail_image( $pdf_id )

it works similar to wp_get_attachment_image and it will return something like

Hooks

pdf_thumbnail_max_width

Maybe you want to change global PDF thumbnail max_width for a specific PDF file

add_filter( 'pdf_thumbnail_max_width', function( $max_width, $pdf_id ){
    if( $pdf_id == 123 ){
        return 1024;
    }
    return $max_width;
}, 10, 2 );

pdf_thumbnail_max_height

Maybe you want to change global PDF thumbnail max_width for a specific PDF file

add_filter( 'pdf_thumbnail_max_height', function( $max_height, $pdf_id ){
    if( $pdf_id == 123 ){
        return 768;
    }
    return $max_height;
}, 10, 2 );

pdf_thumbnail_quality

Maybe you want to change global PDF thumbnail quality for a specific PDF file

add_filter( 'pdf_thumbnail_quality', function( $quality, $pdf_id ){
    if( $pdf_id == 123 ){
        return 100;
    }
    return $quality;
}, 10, 2 );

pdf_thumbnail_type

Maybe you want to change global PDF thumbnail file type for a specific PDF file

add_filter( 'pdf_thumbnail_type', function( $type, $pdf_id ){
    if( $pdf_id == 123 ){
        return 'png'; // or 'jpg'
    }
    return $type;
}, 10, 2 );

pdf_thumbnail_bgcolor

Maybe you want to change default PDF thumbnail background for a specific PDF file

add_filter( 'pdf_thumbnail_bgcolor', function( $bgcolor, $pdf_id ){
    if( $pdf_id == 123 ){
        return 'black'; // default is 'white'
    }
    return $bgcolor;
}, 10, 2 );

pdf_thumbnail_page_number

Maybe you want to PDF thumbnail page number for a specific PDF file

add_filter( 'pdf_thumbnail_page_number', function( $page, $pdf_id ){
    if( $pdf_id == 123 ){
        return 1; // default is 0
    }
    return $page;
}, 10, 2 );

pdf_thumbnail_filename

Maybe you want to PDF thumbnail filename for a specific PDF file

add_filter( 'pdf_thumbnail_filename', function( $filename, $pdf_id ){
    if( $pdf_id == 123 ){
        return str_replace( '.pdf.png', '.png', $filename );
    }
    return $filename;
}, 10, 2 );

pdf_thumbnail_imagick

Maybe you want to add watermark to PDF thumbnail for a specific PDF file

add_filter( 'pdf_thumbnail_imagick', function( $imagick, $pdf_id ){
    if( $pdf_id == 123 ){
        // add your watermark here
    }
    return $imagick;
}, 10, 2 );

get_pdf_thumbnail_image_attributes

Maybe you want to change attributes for image tag from get_pdf_thumbnail_image function

add_filter( 'get_pdf_thumbnail_image_attributes', function( $attr, $pdf_id ){
    $attr['loading'] = 'eager';
    return $attr;
}, 10, 2 );

pdf_thumbnail_generated

Maybe you want to do something after the thumbnail is generated

add_action( 'pdf_thumbnail_generated', function( $thumbnail_path, $pdf_id ){
    // do somthing with the local file $thumbnail_path
}, 10, 2 );

1. Upload pdf-thumbnail-generator directory to the /wp-content/plugins/ directory
2. Activate the plugin through the ‘Plugins’ menu in WordPress

1.5

• tested on WP 6.9
• new shortcode [pdf_clickable_thumbnail id=”123″] displays clickable PDF thumbnail that will open PDF in new tab on click
• csrf security fix

1.4

• fix: more URL escaping

1.3

• tested on WP 6.6
• escape URL in admin link to prevent XSS

1.2

• tested on WP 6.5

1.1

• tested on WP 6.4

1.0

• First version