Beautiful flipbooks
on your WordPress site

What the plugin adds to your site — and what it doesn't

A plugin is something you let into your own installation, so it is fair to ask what it brings with it. This one is deliberately small. On the front end it outputs a single <div> with one <iframe> inside it, marked loading="lazy" so a flipbook further down a long page is only fetched when the reader gets there.

It enqueues no stylesheet and no JavaScript on the front end. It creates no database tables and adds no admin menu. It does not phone home, count anything, or ask for an API key. Everything that makes the flipbook work runs inside the iframe, on our side — which is also why your page speed score does not move when you add one.

Deactivating it is equally uneventful: the shortcode stops being recognised, so [toombler id="…"] appears as plain text in your post until you remove it. Nothing is left behind in the database, because nothing was put there.

The text version, and why it is worth switching on

A flipbook is a picture of your pages. That is fine for a reader with working eyes and a mouse, and useless for a screen reader, which finds a frame and nothing to read. Adding text="1" to the shortcode puts a collapsible Read the text version panel under the book, filled with the actual text layer from your PDF.

The fetch happens on your server, not in the visitor's browser, and the result is kept in a WordPress transient: twelve hours when text was found, one hour when it was not — so a flipbook whose text is still being extracted picks it up shortly instead of a day later. At most 60,000 characters are stored, which is more than a typical brochure and stops a 400-page manual from filling your options table.

There is a second reason to use it, less noble but real: that text is on your page, in your HTML, under your domain. A search engine reading the post sees what the document actually says instead of a frame it cannot enter. If you publish catalogues or newsletters that you want found, this single attribute does more than anything else on this page.

It only works for PDFs that contain real text. A scan without OCR has no text layer, so the panel stays away rather than showing an empty box.

Requirements, versions and licence

The plugin needs WordPress 5.8 or newer and PHP 7.4 or newer, and it is tested against the current WordPress release. Those are low bars on purpose: the code uses nothing exotic, so it keeps working on hosting that is a few years behind.

Because the shortcode is an ordinary shortcode, it works in the block editor, in the classic editor, in a text widget, and in page builders such as Elementor, Divi, Beaver Builder and Bricks — anywhere that renders shortcodes. The Gutenberg block is a convenience on top, not a requirement.

It is free software under the GPL, version 2 or later, the same licence as WordPress itself. You may read it, change it, and run your own fork on your own sites.

How it handles what you type

Anything that ends up in a page's HTML deserves a sceptical look, so here is what happens to your attributes. The File ID must match [A-Za-z0-9_-] and be between ten and sixty characters; anything else is refused with a visible message rather than pasted into a URL. Width and height go through absint(), so a stray letter becomes the default instead of breaking the layout. The assembled URL is escaped before it reaches the src.

One thing is worth knowing because it surprises people: WordPress silently discards shortcode attributes it does not recognise. Write hight="600" and nothing goes wrong — you simply get the default height and no warning anywhere. If an option seems to do nothing, check the spelling against the table above before looking further.

The plugin makes exactly one request from your server to ours, and only when text="1" is set: it asks for the text of that one flipbook. Nothing about your visitors is sent, because nothing about your visitors is known to it.

Block or shortcode?

They render the same HTML, so this is a question of how you like to work. The block gives you a live preview in the editor and a sidebar with the options as real controls, which is easier when you are trying out sizes. The shortcode is text, which makes it easy to copy between posts, to paste into a page builder, and to search for later when you want to find every flipbook on the site.

If you maintain the site for someone else, the shortcode has one practical advantage: it survives a theme change, an editor switch and a page builder migration without needing to be rebuilt. For a comparison of the plugin against the three other ways of embedding — plain iframe, JavaScript snippet and oEmbed — see the guide on embedding a PDF in WordPress.