NinjaWeb

NinjaWeb Smart Media Optimizer is a local media optimization engine for WordPress site owners, maintainers, and agencies who want controlled image processing without relying on an external optimization service.
The plugin runs inside WordPress using the image tools available on your server. There are no API keys, no credits, no monthly image caps, no required CDN, and no subscription gate for the core workflow. You control when images are scanned, queued, optimized, retried, and restored.
The workflow is designed for transparency. Instead of hiding the process behind a remote service, the plugin provides a real-time Media Engine panel with progress, current job details, live activity logging, pause/resume/stop controls, failed-item retry, and clear restore options when backups are available.
Key features:
<ul>
<li>Local optimization using your WordPress/server image tools</li>
<li>No external API, no credits, no CDN dependency, and no required subscription</li>
<li>Real-time bulk optimizer with progress, pause, resume, stop, retry, and live activity log</li>
<li>Optimize used images, all pending images, the full Media Library, or selected images</li>
<li>Usage-aware scanner for featured images, galleries, common content embeds, and upload URLs</li>
<li>Local WebP generation for JPEG and PNG images when supported by the server</li>
<li>Search and filter Media Library images from one screen</li>
<li>Oversized-image detection based on your configured maximum width</li>
<li>Compression presets with simple guidance</li>
<li>Custom quality mode for advanced control</li>
<li>Maximum-width resizing for large uploads</li>
<li>Optional minimum file-size threshold so tiny images can be skipped</li>
<li>Optional PNG to JPG conversion modes for non-transparent PNG files, disabled by default</li>
<li>Transparent PNG protection</li>
<li>Backup originals before changes</li>
<li>Restore selected images or restore all originals when backups exist</li>
<li>Original Kept status when optimization would not reduce the file size</li>
<li>Regenerate WordPress attachment metadata after changes</li>
<li>Preserves attachment IDs instead of replacing posts or breaking relationships</li>
<li>Global dashboard stats for total images, optimized images, pending images, backups, and optimized media size saved</li>
</ul>
NinjaWeb Smart Media Optimizer is intentionally built for a deliberate, auditable workflow rather than remote black-box processing.
Official documentation, updates, and support: 
<a href="https://ninjaweb.com.au/products/smart-media-optimizer/" rel="nofollow ugc">Smart Media Optimizer by NinjaWeb</a>

NinjaWeb Smart Media Optimizer

Free local image optimizer. No API, credits, or CDN. Bulk optimize, WebP, backups, restore, and used-image queues.

dmry

This plugin enables you to automatically resize every user-posted image which is larger than given dimensions. Original plugin writen by <a href="http://www.ncode.nl/vbulletinplugins/" rel="nofollow ugc">Jorrit Schippers</a> for vBulletin.
Some features:
<ul>
<li>No resizing</li>
<li>Enlargement in the same document</li>
<li>Enlargement in the same window</li>
<li>Enlargement in a new window</li>
<li>Enlargement in modal window</li>
<li>Any JavaScript Framework is not required</li>
</ul>
It also adds an information bar (which is not displayed when the image is too small) giving information about the original dimensions and filesize.
Localization:
<ul>
<li>Belorussian (be_BY) – <a href="http://www.fatcow.com/" rel="nofollow ugc">FatCow</a></li>
<li>Arabic (ar_AR) – <a href="http://linuxawi.com/" rel="nofollow ugc">ZAH3R</a></li>
<li>Japanese (ja) – <a href="http://blog.osakana.net/" rel="nofollow ugc">osakanataro</a></li>
</ul>

nCode Image Resizer

This plugin enables you to automatically resize every user-posted image which is larger than given dimensions.

NinjaWeb Smart Media Optimizer vs nCode Image Resizer