Altagonist

Description

Alt tags matter. They help visually impaired users understand your images, improve your search engine rankings, and are a basic requirement for web accessibility. Writing them by hand for every image in your media library is tedious. Altagonist takes care of it for you.

Point it at your images, click Generate, and get descriptive alt tags written by AI, saved directly into your WordPress media library.

How it works

  1. Open the Altagonist page in your WordPress admin
  2. Browse your media library and select one or more images
  3. Click Generate. Image info is sent to the Altagonist API and an alt tag comes back
  4. The alt tag is saved to your media library, just like you typed it yourself

Features

  • AI-powered alt tag generation using computer vision
  • Supports JPEG, PNG, GIF, and WebP. SVG, AVIF, TIFF, and BMP are converted automatically
  • Bulk generation: select multiple images and process them all at once
  • Three quality levels (Lite, Medium, High). Higher quality uses more page context for better results
  • 70 languages supported
  • Auto-generate on upload: enable in Settings to tag images the moment they are uploaded
  • Filters to show only images with missing alt tags so you can close gaps quickly
  • Alt tags are saved to the standard _wp_attachment_image_alt field, fully compatible with all themes and plugins

External service

Images are processed externally. When you trigger alt tag generation (manually or via auto-generate on upload), the following data is sent:

  • The image URL (or the image itself as base64 if the URL is not publicly reachable)
  • Site name, page title, and page content (amount depends on the quality setting)
  • Selected language and quality level
  • Your license key and site URL

No data is sent unless you actively trigger generation or have auto-generate on upload enabled. Images are processed in real-time and are not stored.

Screenshots

  • Browse your media library and generate alt tags with one click. Descriptive AI-written captions appear in the table.
  • Settings page: license key, languages to enable on the main page, and auto-generate-on-upload options.
  • Row detail showing a generated alt tag saved to WordPress.
  • Auto-Generate on Upload: have alt tags created automatically when new images are uploaded.

Installation

  1. Upload the altagonist folder to /wp-content/plugins/
  2. Activate the plugin in Plugins > Installed Plugins. A free license is provisioned automatically on activation.
  3. Open the Altagonist page and start generating alt tags

FAQ

Do I need an account?

No. A free license is automatically provisioned when you activate the plugin. You only need an account at altagonist.com if you want to manage your subscription or upgrade to a paid plan.

Is it free?

You can use up to 50 credits per month freely. Paid plans are available for higher volume needs.

What image formats are supported?

JPEG, PNG, GIF, and WebP work natively. SVG, AVIF, TIFF, BMP, and most other formats are automatically converted before processing, so you don’t need to worry about format compatibility.

Are my images stored?

No. Image info is sent to the Altagonist API only at the moment of generation and is not retained.

Which languages are supported?

Alt tags can be generated in 70 languages, including English, Dutch, French, German, Spanish, Portuguese, Italian, Japanese, Chinese, Korean, Arabic, and many more.

Can it tag images automatically as I upload them?

Yes. Enable Auto-Generate on Upload in Settings and choose your preferred language and quality level. New uploads will be tagged automatically.

Where does the alt tag get saved?

To the standard WordPress _wp_attachment_image_alt post meta field, exactly where WordPress, themes, and page builders expect to find it.

Reviews

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Contributors & Developers

“Altagonist” is open source software. The following people have contributed to this plugin.

Contributors

Translate “Altagonist” into your language.

Interested in development?

Browse the code, check out the SVN repository, or subscribe to the development log by RSS.

Changelog

1.0.1

  • Fixed pagination showing duplicate images across pages
  • Added per-page selector (20/50/100)
  • Improved auto-provisioning on activation
  • Better error handling for unreachable images (automatic retry with upload)
  • Prefix compliance improvements

1.0.0

  • Initial release