Means of Regenerating PDF Thumbnails in your WordPress
One of the users recently asked if generating PDF thumbnails for use in WordPress was possible. Although WordPress 4.7 or higher features thumbnail previews of all new PDF files, the change has no impact on older uploads. Here are the means of generating PDF thumbnails in your WordPress for uploads that are older.
Reasons and who should Regenerate PDF Thumbnails
PDF thumbnail previews were first introduced by in WordPress 4.7. The feature works by creating image previews of the initial page of any PDF file you upload via the media upload. But, the effects of the features apply only to new PDF files you upload after you have upgraded your site to WordPress 4.7 or higher.
To display a thumbnail preview of attachment pages, you must apply the PDF plugin, because the appearance of all PDF files that are old will be a general symbol in your WordPress media library.
If you happen to be uploading PDF files regularly on your WordPress, you must regenerate thumbnails of older PDF uploads.The thumbnail regeneration of older PDF uploads resembles that of regenerating thumbnails of your images after you have added images of different sizes in your WordPress theme. Nevertheless, the plugins are currently not supporting PDF files. Here are the means of regenerating PDF thumbnails of older uploads in your WordPress.
WordPress Regeneration of PDF Thumbnails
Ensure you have upgraded your WordPress to WordPress 4.8 before you start the process. Besides, ensure you have installed ImageMagick extension on the server you are using. Upload a PDF file on your WordPress site to test your ImageMagick, and proceed with the process when the extension displays a thumbnail preview of the PDF file.
However, the plugin we will use in our case can generate thumbnails of both older files and images. Also, it is recommendable you backup your content, folder or even your WordPress site before you start regenerating thumbnails.
To start the process, install the Force Regeneration Thumbnails plugin, and ensure you have activated it. Since GitHub hosts the plugin, it is important you check the guide on the Installation of plugins obtained from GitHub if you have never installed plugins from the site before.
After activating the plugin, move to tools and open the Force Regenerate Thumbnails page. You will be able to regenerate thumbnails of all PDF files and images, you have ever uploaded on WordPress site using the media upload.
To initiate the regeneration of the thumbnails, click the button” Regenerate All Thumbnails,” and processing will start. Based on the number of PDF files and images, the processing time of images on your site by the plugin will vary.
After the plugin completes processing PDF files and images on your site, move to media and open the library. Here, you will see all thumbnails previews of the old PDF upload.
Apart from regenerating all thumbnails at once, the plugin enables you to regenerate thumbnails from specific files. The option of regenerating thumbnails individually is suitable if you have fewer PDF files.
To regenerate files individually, move to the media bar, open the library page, and then click the list view for list view display. Now move your mouse over a PDF file, and a ‘Force regenerate thumbnails’ link will appear. To regenerate thumbnails of the file, click the link.
After regenerating thumbnails of all old PDF uploads, you are safe to delete or deactivate the plugin, because thumbnails regenerated will not be removed.