Alexandru Vornicescu

If you want to resize featured images (post thumbnails) on the fly for your posts automatically then this plugin can help you.
To take effect just open a post or page and all featured images in that post will be resized to a normal size.
This plugin can be very useful after a theme install.
It can be an alternative for Regenerate Thumbnails plugin.
I think this plugin is better because you will not need to wait before all images are resized for all different sizes, just for images that are need to resize.
The plugin will keep the original copy of all image files.

Resize Post Thumbnails

This plugin is very useful and time-saving! Works fast and doesn't need any extra steps.

Best alternative to Regenerate Thumbnails

This plugin will resize post thumbnails on the fly.

ShortPixel

A free, fast, easy to use, stable and frequently updated plugin to resize your images after upload. Supported by the friendly team that created <a href="https://wordpress.org/plugins/shortpixel-image-optimiser/" rel="ugc">ShortPixel</a> 🙂
This plugin automatically resizes images (JPEG, GIF, and PNG) when they are uploaded to within a given maximum width and/or height to reduce server space usage, speed up your website, save you time and boost your site’s SEO. 
Imagine that nowadays images can be over 4-5MB and using this plugin you can reduce them to 100-200KB with no extra effort on your side!
In addition, the plugin can force the re-compression of uploaded JPEG images and convert PNGs to JPEG (if they don’t have a transparency layer), regardless of whether they are resized or not.
Is that simple, just give it a try, it is safe and free! 🙂
Other plugins by <a href="https://shortpixel.com" rel="nofollow ugc">ShortPixel</a>:
<ul>
<li><a href="https://wordpress.org/plugins/fastpixel-website-accelerator/" rel="ugc">FastPixel Caching</a> – WP Optimization made easy</li>
<li><a href="https://wordpress.org/plugins/shortpixel-image-optimiser/" rel="ugc">ShortPixel Image Optimizer</a> – Image optimization & compression for all the images on your website, including WebP & AVIF delivery</li>
<li><a href="https://wordpress.org/plugins/shortpixel-adaptive-images/" rel="ugc">ShortPixel Adaptive Images</a> – On-the-fly image optimization & CDN delivery</li>
<li><a href="https://wordpress.org/plugins/enable-media-replace/" rel="ugc">Enable Media Replace</a> – Easily replace images or files in Media Library</li>
<li><a href="https://wordpress.org/plugins/regenerate-thumbnails-advanced/" rel="ugc">reGenerate Thumbnails Advanced</a> – Easily regenerate thumbnails</li>
<li><a href="https://wordpress.org/plugins/wp-svg-images/" rel="ugc">WP SVG Images</a> – Secure upload of SVG files to Media Library </li>
</ul>
Get in touch!
<ul>
<li>Email <a href="https://shortpixel.com/contact" rel="nofollow ugc">https://shortpixel.com/contact</a></li>
<li>Twitter <a href="https://twitter.com/shortpixel" rel="nofollow ugc">https://twitter.com/shortpixel</a></li>
<li>Facebook <a href="https://www.facebook.com/ShortPixel" rel="nofollow ugc">https://www.facebook.com/ShortPixel</a></li>
<li>LinkedIn <a href="https://www.linkedin.com/company/shortpixel" rel="nofollow ugc">https://www.linkedin.com/company/shortpixel</a></li>
</ul>

Resize Image After Upload


Unfortunately, Wordpress administrators do not deal with this at all, and all it takes is one careless editor and the administrator has a lot to do for many hours. With this plugin, servers are no longer filled with unnecessary giant images that are ultimately useless and just lie dead on the server and take up space. Lots of space.


Thanks for fixing the big images issue

Automatically resize your images after uploading using this plugin. Specify height&width, the plugin will do the rest quickly and transparently.

Resize Post Thumbnails vs Resize Image After Upload