Kiminori Shimada - ?? ??

You will be able to resize smartphone, tablet PC for the image in the article. This Plugin is the ideal tool for Responsive Web design.
<h3>Plug-in Usage</h3>
In order to use this plug-in, there is no special knowledge. 
enable the plug-in, will start running.
If necessary, from the configuration screen, you can also specify the width of each device.

Auto Image Resize

mores

This plugin is basically just a little improvement of <a href="https://wordpress.org/extend/plugins/resize-at-upload/" title="Resize-At-Upload" rel="ugc">Resize-At-Upload</a>, a fabulous plugin by A. Huizinga.
The plugin will automatically resize an image upon upload, depending on the maximum width and height that you define. Gone are the days when you, or your client, will ruin a site’s layout by uploading a huge file with 25 megapixels. 
Be advised: there is no backup, no copy of the originally uploaded image.
The plugin uses a class originally from Jacob Wyke (www.redvodkajelly.com).

Resize at Upload Plus

Automatically resize (i.e. scale down) images after uploading. Save disk space and preserve your layout

Auto Image Resize vs Resize at Upload Plus