Pavel

The “Light Code Block” plugin is a simple and lightweight solution for inserting and displaying code snippets in posts and pages. 
It works by adding a custom “LC” button to the TinyMCE (Classic) editor or a code block in the Gutenberg editor.
The inserted code will be shown on the front end in a clean, readable format.
<h3>Usage</h3>
<ul>
<li>Install and activate the plugin.</li>
<li>Go to the post or page edit screen.</li>
<li>In the TinyMCE (Classic) editor, click the “LC” button in the toolbar.</li>
<li>In the popup window that opens, paste or write your code, and click OK.</li>
<li>Save or update your post.</li>
</ul>
The code will be saved inside a special block and displayed on the front end within a <code><pre></code> tag with the class <code>mce-simple-code-block</code> (i.e., <code><pre class="mce-simple-code-block">...</pre></code>).
To insert code using the Gutenberg editor, you first need to add a Classic (TinyMCE) block, and then use it to insert your code.

Light Code Block

The "Light Code Block" plugin is the simplest and lightest plugin for inserting and displaying code.

digihero

Auto SyntaxHighlighter is a WordPress Code highlight plugin.
It’s used alexgorbatchev SyntaxHighlighter JavaScript package.
Autoload SyntaxHighlighter only requisite js files and display you code.
Github address: https://github.com/wkii/Auto-SyntaxHighlighter
Support languages see: SyntaxHighlighter Brushes.
Full Support for : AppleScript, ActionScript3, Bash/shell, C#, C++, CSS, Delphi, Diff, Groovy, JavaScript, Java, Perl, PHP, Plain Text, Python, Ruby, Sass, Scala, SQL, Visual Basic and XML/HTML…
It’s advantages:
<ul>
<li>Don’t write database;</li>
<li>Don’t need settings;</li>
<li>Deactivate plugin code can also display properly;</li>
<li>Code can switch visual editing mode or HTML mode;</li>
<li>With the w3c standards;</li>
<li>Insert code small tools;</li>
<li>Automatic and only loading requisite files;</li>
<li>Write code to support non-administrator</li>
</ul>

Auto SyntaxHighlighter

Auto SyntaxHighlighter is a WordPress Code highlight plugin. Use editor botton, in the pop-up window, paste or write your code, oh, very simple.

Light Code Block vs Auto SyntaxHighlighter