Alexandru Vornicescu

This is a WordPress plugin.
If you want to resize images in your posts automatically so the page will load faster and use less bandwidth then this plugin can help you.
To take effect just open a post or page and all images in that post will be resized to a smaller version.
It will replace the URLs of the images that are too big with URLs of the resized images that will fit into the posts.
The plugin will keep the original copy of all image files.
Note: With version 4.3 now you can resize images in Text Widgets.
Note: The filter – “wp_make_content_images_responsive” will be deactivated because with this plugin we will not need anymore.

Resize Images In Posts

This plugin will resize images in your posts.

yoshi

Multifile Upload plugin adds some features to the WordPress’ default upload interface. You will be able to upload more than one file at a time. You can also resize the original image by specifying the size and change the thumbnail size when uploading.

Multifile Upload

This plugin allows WP's upload interface to handle multiple files at a time. User can also change the original and thumbnail image sizes.

Resize Images In Posts vs Multifile Upload