nixtool

Nix Image Optimizer helps optimize your WordPress media library by converting supported image uploads to WebP automatically and giving you tools to manage existing images, generate lightweight featured images, and improve image SEO metadata.
Features:
<ul>
<li>Automatically converts new JPG, JPEG, PNG, and AVIF uploads to WebP.</li>
<li>Bulk-compresses existing Media Library images.</li>
<li>Shows compression statistics in a Media Log.</li>
<li>Adds optional watermark support before compression.</li>
<li>Generates blog-style featured images from post title, category, author name, and avatar.</li>
<li>Supports custom featured image background colors, gradients, typography, and output dimensions.</li>
<li>Auto-fills missing image ALT text and attachment descriptions from post content.</li>
<li>Includes Basic and Advanced Image SEO Metadata modes.</li>
<li>Scans and backfills existing posts with safe generated-metadata rules.</li>
<li>Includes an unused media scanner and cleaner.</li>
<li>Works with WordPress Media Library metadata and regeneration flow.</li>
</ul>
<h3>External services</h3>
This plugin can connect to the WordPress avatar system, which commonly uses Gravatar, when the Featured Image Generator is configured to include the post author’s avatar.
When the avatar option is enabled, the plugin requests the author’s avatar URL while showing the featured-image preview in the WordPress admin and while generating a featured image for a post or page. WordPress builds that avatar URL from the author’s user account email address according to the site’s normal avatar settings. The plugin downloads the avatar image from that URL so it can draw the circular author avatar into the generated featured image. If the avatar option is disabled, or if no avatar URL is available, the plugin does not request the avatar image and uses a local placeholder shape instead.
The avatar service is provided by Gravatar/Automattic: 
Terms of Service: https://wordpress.com/tos/ 
Privacy Policy: https://automattic.com/privacy/

Nix Image Optimizer

Convert images to WebP with bulk compression, media log, watermarking, image SEO, featured image generation, and unused media cleanup.

Andrew Gunn

RyanVanEss

Orion Group LLC

Mitch Menghi

Auto generate clean ALT tags for your images as they are uploaded. Automatically removes hyphens, periods and other characters to generate clean alt tag names. 
SEO Auto Image Tags automatically updates the title and alt tag for every image uploaded with a clean Title Case version of the file name! Don’t waste your time manually craeting SEO Friendly Tags, let SEO Auto Image Tags do the work for you! 
You can run the database updater to create, update, or delete image tag data for all images in the media library. All with a lightweight and efficient clientside script to EVERY image is properly tagged.

SEO Auto Image Tags

Auto generate clean ALT tags for your images as they are uploaded. Removes hyphens, periods and other characters to generate clean alt tag names.

Nix Image Optimizer vs SEO Auto Image Tags