Image optimization services and plugins are most commonly known on which ones work well. But it is not as common to know how to optimize site assets that happen to be PDF files.
When normally creating a PDF or exporting a PDF that will be uploaded on your site the file will not be optimized and depending on the images or the number of pages that the PDF file is the file could be 14-30 MB in size. PDF files like image files can be easily optimized using a service with a plugin or a site to optimize the file before upload.
One of the few image optimization services that do all includes PDF files is ImageRecycle. You can sign up for a free trial which can be used for 15 days or ImageRecycle also offers a number of one-offs paid plan options. The pricing for the one-time membership plans is $10 for 1GB of content, $20 for 3GB of content or $50 for up to 10GB.
ImageRecycle provides a solid easy to use plugin for WordPress. After you have installed and activated the plugin it will ask you to enter your ImageRecycle account credentials the plugin will then automatically pull in the accounts API key.
You can change the optimization quality settings for ImageRecycle based on file type. New images and PDF files will be optimized on upload into the media library of the site or you can bulk optimize existing images and PDF files in the media library from;
Media > Image recycle
You can then select which of the images and PDF files you want to optimize and they will be placed into a queue to process.
Manage all your WordPress sites with the MainWP Dashboard
WordPress Management for Professionals
All MainWP Pro Extensions are available through one of our convenient bundled packages.
Smallpdf is an online site service that includes an easy-to-use way to optimize PDF files. Go to the compress PDF site and then select the locally stored PDF file that you want to optimize. Now you will have a number of compression options even using the basic compression will get you decent gains. After the file has been optimized you can now locally download the file, store it to Small PDF if you have a pro account or you can upload it to Google Drive or Dropbox.
Also making sure that PDF files that are being served on your site are optimized will improve loading or download times for users of the site and will also speed up your site and reduce file storage usage.