brajesh

Embed Iframe is a plugin that will let you embed iframe – an HTML tag that allows a webpage to be displayed inline with the current page, in a WordPress post. Although an iframe can lead to a complicated website, it can be very effective when used appropriately.
<h3>Usage</h3>
Use following tag to insert another page in post using iframe
<pre><code>[iframe url width height]
</code></pre>
e.g.
<pre><code>[iframe http://www.example.com 400 500]
</code></pre>

Embed Iframe

Allows the insertion of code to display an external webpage within an iframe.

Scott (@scottsweb)

Fillet adds a new IFrame button to the toolbar in the WordPress visual editor. By using a <a href="https://codex.wordpress.org/Shortcode" rel="nofollow ugc">shortcode</a>, it allows for safer, responsive and future proof embeds.
The chosen width and height for an IFrame embed is converted into a ratio which is used to scale your embeds across different devices.
<a href="http://scott.ee/" title="WordPress web design Hampshire" rel="nofollow ugc">a plugin by Scott Evans</a>

fillet

Safely embed responsive IFrames in the WordPress text editor.

Embed Iframe vs fillet