Lazy Load for Videos

Where can I see this plugin in use?
For example, on www.kweber.com/lazy-load-videos/.
Which video platforms are supported?
Videos from the biggest video platform, Youtube (https://youtube.com), and Vimeo (https://vimeo.com) are supported.
The plugin isn't working with Jetpack...
"Jetpack" by WordPress.com offers some useful extensions. Only one of them makes Lazy Load for Videos break – the "Shortcode Embeds" extension. So simply disable the extension. (In order to see a "Deactivate" button for "Shortcode Embeds" on the Jetpack's extension overview, you must click on "Learn More".)
Does the Lazy Load for Videos plugin work when there is more than one video on the same page?
Yes. The plugin works on single posts and pages as well as on archive pages with several posts and videos.
Should I use the Lazy Load for Videos plugin?
Yes!
Why?

If you want to speed your site up, this plugin is for you. Especially on sites with many embedded videos this plugin is gold. There are manz reasons why you should make your site faster, see next question.
The plugin is really lightweight, has no dependencies and does neither blow your performance nor your database up.
By loading the videos only when the user clicks on the preview image, no unnecessary JavaScript is loaded. You may know this issue: (Defer) Parsing of JavaScript. "In order to load a page, the browser must parse the contents of all tags, which adds additional time to the page load. By minimizing the amount of JavaScript needed to render the page, and deferring parsing of unneeded JavaScript until it needs to be executed, you can reduce the initial load time of your page." (Source: https://developers.google.com/speed/docs/best-practices/mobile#DeferParsingJS)
Video preview and play button are scalable and optimized for mobile devices.
Finally, Lazy Load for Videos is really easy to use. Simply upload and activate the plugin.

Search engines, especially Google, love speedy sites! So you will be higher ranked in search results.
Consequently, you get more visitors.
Fast sites lead to higher visitor engagement and returning visitors.
Faster sites increase conversions.
Potentially more $$ for your business!

How can I calculate my Google PageSpeed Score?
PageSpeed Insights is a service by Google to help you optimize your site's performance. You can analyse your site using a browser extension or online, more information: https://developers.google.com/speed/pagespeed/
How to embed videos in WordPress?
Easily insert the URL to your content (e.g. Youtube video) into a post or page. The URL must be on its own line and must not be hyperlinked. "WordPress will automatically turn [the URL] into a YouTube embed when the post is viewed." (Source: https://codex.wordpress.org/Embeds)
Inserting a Youtube <iframe> (instead of the plain URL) is deprecated and not supported by Lazy Load for Videos.
How to disable lazy-loading of a single video?
Append &lazyload=0 to the video URL.
How to add support for custom post types?
UPDATE: Since plugin version 2.1.2, every custom post type is supported automatically. So you can ignore the following instructions. They will be removed with one of the next updates.

You can use a filter to add support for a custom post type (since version 2.0.4).
Replace 'post_type_label' with the name/label of your custom post type.

/**
* Set post types that shall support Lazy Load for Videos
*/
function lazyload_videos_set_post_types( $post_types ) {
$post_types[] = 'post_type_label';
return $post_types;
}
add_action( 'lazyload_videos_post_types', 'lazyload_videos_set_post_types' );

How to use a custom play button?
For now, you can choose the "Youtube button image" from the play button drop-down list, then add the following custom CSS that includes a link to your custom CSS play button image:

`

.preview-youtube .lazy-load-youtube-div, .lazy-load-vimeo-div {
background-image: url(INSERT-YOUR-URL-HERE.../images/play.png);
}
`

Feature versions might include an option to change the colour of your CSS-only buttons using a colour picker and might also include an option to directly upload the desired button image.
How to lazy load playlists?
Similar to a single video, insert the playlist URL in the following format:
https://www.youtube.com/watch?v=dkfQFih23Ak&list=PLRQFBJ3mkjnxaPhAVOzjxxv_0yr8XE0Ja (the other format - https://www.youtube.com/playlist?list=... - is not supported currently).
Note that playlists are not working when you're using the pre-/post-roll feature.
How can I report security bugs?
You can report security bugs through the Patchstack Vulnerability Disclosure Program. The Patchstack team help validate, triage and handle any security vulnerabilities. Report a security vulnerability.
Known bugs - this plugin may not work correctly when one of the following plugins is activated...

"YouTube" (https://wordpress.org/extend/plugins/youtube-embed-plus/)
"Shortcode Embeds" extension within Jetpack, see answer above (https://jetpack.me/support/shortcode-embeds/)
"BuddyPress" (https://wordpress.org/plugins/buddypress/)
Thumbnails from Vimeo videos in "Privacy Mode" are not supported because Vimeo’s API doesn’t deliver thumbnails for those videos.
[???]