WP AI Alt Text Generator

Accessibility shouldn't be manual.

WP AI Alt Text Generator scans your WordPress Media Library, finds every image missing alt text, and generates accurate, WCAG-compliant descriptions using Claude AI vision — one click per image or all at once.

What It Does

• Dashboard under Media → AI Alt Text shows all images in a grid with coverage stats
• Missing / All / Has Alt Text filter tabs
• ✨ Generate button per image — Claude vision reads the image and writes descriptive alt text
• Auto-saves immediately after generation — no extra clicks
• ✨ Generate All Missing — processes every image without alt text sequentially with a live progress bar
• Editable — review and tweak before or after saving
• Coverage meter — shows % of images with alt text at a glance

How It Works

1. Fetches the image from WordPress (via base64 encoding)
2. Sends it to Claude Haiku's vision model with an accessibility-focused prompt
3. Claude returns a concise alt text (max 120 characters), no "Image of" or "Photo of" prefix
4. Saved to _wp_attachment_image_alt — the standard WordPress alt text field used by all themes and Gutenberg

File Structure

wp-ai-alt-text/
├── wp-ai-alt-text.php          # Bootstrap
├── includes/
│   ├── class-generator.php     # Claude vision API + base64 fetch
│   └── class-admin.php         # Media Library dashboard + AJAX handlers
├── assets/
│   ├── admin.css               # Grid UI, cards, progress bar
│   └── admin.js                # Generate, save, bulk loop with progress
└── README.md

Installation

1. Upload the wp-ai-alt-text folder to /wp-content/plugins/
2. Activate the plugin
3. Go to Media → AI Alt Text
4. Enter your Claude API key (from console.anthropic.com)
5. Click ✨ Generate on any image, or Generate All Missing to bulk-process

API Cost

• Model: claude-haiku-4-5 with vision
• ~$0.002 per image (input image tokens + short text output)
• 100 images ≈ $0.20

Part of the 30-Day WordPress AI Plugin Series

Day 4 of building one open-source WordPress + AI plugin every day.

• Day 1: WP RAG FAQ
• Day 2: WP Content Repurposer
• Day 3: WP Smart 404
• Day 4: WP AI Alt Text Generator ← you are here

Follow along: bilalmahmood.dev

License

GPLv2 or later