While embedding PDF files in your blog posts, make sure the file size is not too large. It may slow down your post page significantly which in turn may hurt the quality of your website from SEO perspective.
Always test the PDF-embed on a staging site before moving it to the main blog. Do not embed mutiple PDF files in a single blog post. Also ensure your plugin supports a placeholder for the loading PDF file.
vanilla-pdf-embed - This is one of the simplest yet useful plugins to easily display embedded PDF files within your blog posts. Simply upload the file in your media library and grab its URL for embedding. Paste this URL into the place where you want the PDF file to appear in an embedded form. You can also use the [pdf] short tag with custom parameters to fine tune the embedding features. These custom parameters include adjustments for width, height and the title for the file link. The PDF files embedded through it may not display on certain mobile browsers and in some legacy browsers.
CopySafe PDF Protection - As the name suggests, apart from allowing you to embed PDF documents in blog posts, it also ensures they're safe from copying and download action. This ensures visitors cannot steal your content presented through the PDF file. Power users can also take advantage of its dynamic PDF embedding feature possible through JavaScript. One can also tweak and adjust the size of the viewable area for better reading experience. You can also customize the level of protection on per post or per page basis. It also prevents hotlinking of all your PDF files embedded in the posts.
PDF Embedder - This excellent PDF embedding solution is one of my favorites. If you have a responsive design, this plugin automatically adjusts the size of the viewable area for clean and unobtrusive reading. It has a handy shortcode for easily embedding the file at the desired location. You can even specify the preferred width of the embedded PDF file. It also includes handy previous and next buttons for easy navigation of the file. Instead of fluid width, you can also instruct this plugin to keep the width of the PDF file fixed. I'm sure you're going to love its auto-resizing feature. Do once give it a try.
PDF Light Viewer Plugin - You can use this plugin to embed both large and small PDF files within your blog posts. It has several impressive features like lazy loading of file pages which is ideal when embedding a huge file. It also shows thumbnails of pages so that visitors can easily navigate through the pages. Bloggers using s2Member plugin will find this solution very handy as it tightly integrates with the former membership framework. It can also be used on multilingual blogs and is extremely developer friendly to help you customize it easily. First-time plugin users can also read its documentation.
Google Doc Embedder - This popular PDF embedding plugin has a large user base and doesn't require any 3rd party plugin or script to work smoothly. It's not just PDF files, but this plugin can embed over a dozen other types of file formats within posts and pages. You can upload your PDF file on an external storage service and can provide its direct URL to the plugin. It is also translated into several popular languages. It works seamlessly with all popular browsers including mobile browsers too. Before embedding the PDF files on a live post through this plugin, do once test it in preview mode.
Embed Any Document - The name itself tells you clearly that this plugin can be used to embed different types of files within blog posts. Users can directly upload and embed the PDF file from within the post editor making the entire process easy. Bloggers can choose between two supported file viewers to give the best experience to their readers. The files embedded through this plugin renders seamlessly without any issues in desktop as well as in mobile browsers. Since the embedded part is clean and clutter free, it gels well with almost any theme. I've used this plugin for one of my clients.
Cloud Services Viewer - This is another impressive document embedding plugin which supports PDF file formats too. Once embedded, bloggers can easily edit and change the contents of the file without any worries. The updated file is automatically pulled to present the latest version to the readers. You'll need to register for a free cloud storage service account before you can start using this plugin. This plugin does not rely on any external software for its working. It also has a slideshow feature for viewing the PDF file in that format. It's a lightweight and well-maintained PDF embedding plugin.
GroupDocs Viewer - If your blog visitors are mostly using modern web browsers, you can take advantage of this plugin that seamlessly embeds and displays PDF files. The file resizes itself within responsive layouts and the rendered text is sharp and crisp. It works on all major platforms and does not need any external script or a software solution. The available navigation controls within the embedded PDF file are very user-friendly. This plugin supports embedding of over 3 dozen different file formats making it one of the most powerful and flexible plugins in its category. It's a premium plugin worth trying.
Google Drive Embedder - If you're storing your PDF files on Google drive, then this plugin is an ideal solution for you. While composing posts, you can directly access your Google Drive files within a popup to easily select the PDF file you want to embed in the post. You can also fine-tune the access settings of the embedded file. This plugin relies on Google Apps Login plugin to provide you direct access to Google Drive. You'll need a Gmail or a working Google Apps account for the proper working of this plugin. Business users can take advantage of its premium support and service with added features.
File Away - This is an all-in-one plugin to list, highlight and embed different types of text and media files in your blog posts including the PDF file format. It has tons of customization options which can be utilized both by normal and power users to enrich the file embedding experience. It uses a customized Lightbox style container to show embedded PDFs making it quite easy to read and navigate the content. You can also customize the device based settings such that only desktop visitors see the file while the mobile traffic does not. Advanced users can also use custom CSS with this plugin.