Taylor Callsen

Automatically populates Alt and Title tags for images featured in posts and pages, pulling directly from the values set in the Media Library. This makes it easy to manage your image metadata centrally in one place (the Media Library). Plugin also supports the ability to override the Alt/Title tag Media Library values by placing an Alt/Title tag directly on the attachment in the WordPress WYSIWYG Editor.
Tag population only occurs when viewing the post or page, and does not occur in the WYSIWYG editor.

Auto-populate Image ALT Tags from Media Library

Automatically populates Alt and Title tags for images using the values set in the Media Library.

PiotrPress

Clearcode

This plugin adds the <code>[img]</code> shortcode which replaces the <code><img></code> html tag. It’s also enables adding new media to post/page via the ‘Add media’ button by automatically inserting the formatted shortcode code to the editor. 
You can simply add the <code>[img]</code> shortcode with a media ID to display:
<pre><code>[img 123 /]
</code></pre>
or a fully formatted <code>[img]</code> shortcode:
<pre><code>[img 123 align="center" size="full" caption="Sample text" title="Sample text" desc="Sample text" alt="Sample text" url="http://example.com/" /]
</code></pre>
It’s supports <code>srcset</code> and <code>sizes</code> parameters.
<h4>Tips & Tricks</h4>
You can use your own html template file for displaying the <code>img</code> tag by using filter:
<pre><code>add_filter( 'Clearcode\IMG_Shortcode\template', function() { return '/themes/clearcode.cc/templates/img.php'; } );
</code></pre>

CC-IMG-Shortcode

This plugin adds the [img] shortcode which replaces the `` html tag.

Auto-populate Image ALT Tags from Media Library vs CC-IMG-Shortcode