Restores WordPress default functionality prior to version 4.7 where image ALT attributes were automatically generated and put into the HTML code. The ALT attributes were generated from the Caption (if it exists) else from the Title (if it exists) of the image in the Media Library. This plugin utilises Titles in generating ALT text, but does not utilise Captions. The Title used by this plugin, is the main Title of the image as found in the Media Library, not the HTML TITLE attribute of the image (that is something else, which this plugin ignores).

Automatic image ALT attributes

This feature is a time saver for me as my site is image oriented.

Thanks

Automatically generates ALT attributes in image HTML. Restoring WordPress < 4.7 functionality.

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.

Automatic image ALT attributes vs CC-IMG-Shortcode