bijon

Use this qr code wordpress plugin to create a qr code on any site of your WordPress installation. Content can be any text or the current URL of the site where it is embeded.
How to use it:
<ul>
<li>
Use the shortcode [qr-code] within your site to generate a qr code including the URL of the current site
<ul>
<li>It`s not neccessary to give any parameters!</li>
</ul>
</li>
</ul>
<h3>Author</h3>
Bijon Krishna Bairagi
“I create useful free microsites!” 
(https://bijonkrishnabairagi.blogspot.com/” Free qr code online generator”)

QR Code Generator

QR Code Wordpress plugin to insert a QR code in your blog. The qr code contains the current URL or any other text you like.

jweblog

Use this QRCode Generator wordpress plugin to create a image QRCode on any site of your WordPress installation. Use a shortcode in your posts to insert dynamic, customizable posts, pages, images, or attachments based on categories and tags. Visite http://qrcode.jar.io for more information.
The shortcode [qrcode] within your site to generate a qr code including the URL of the current site. This plugin is offered freely by QRCode Generator API Online [qrcode.jar.io].
If you find this plugin useful, please rating this plugin on [https://wordpress.org/extend/plugins/api-qrcode-generator/]
Check website for live demo [http://yoga.jar.io/]
How to use:
<ul>
<li>
Use the shortcode [qrcode] within your site to generate a qr code including the URL of the current site
</li>
<li>
Use the fullowing short code to generate a indivdual qr code with any text content: 
[qrcode content=”text” size=”150px” alt=”text” class=”text”]
</li>
</ul>
<h3>Author</h3>
Jweblog 
“Programming usefull codes for good internet!” 
(http://github.com/jweblog “WP-QRCode Generator”)

API QRCode Generator

Use QRCode Generator to create a image QRCode on any site of your blog.

QR Code Generator vs API QRCode Generator