Outlook Alt Text

A Chrome extension that automatically suggests alt text for images you paste into Outlook web emails. Uses Claude AI to generate accurate, accessibility-friendly descriptions.

Features

• Detects images pasted into Outlook compose
• Generates alt text using Claude AI vision
• Conditional model selection: uses Haiku (cheaper) for simple images, Sonnet (more powerful) for complex images
• Smart prompting: concise for simple images, detailed for schedules/tables/text
• Edit suggestions before applying
• Skip option if you don't want alt text

Installation

From Chrome Web Store (Coming Soon)

Extension will be available on Chrome Web Store soon

Manual Installation (Developer Mode)

1. Clone or download this repository
2. Open Chrome and go to chrome://extensions
3. Enable "Developer mode" (toggle in top right)
4. Click "Load unpacked"
5. Select the outlook-alt-text folder

Setup

1. Get a Claude API key from console.anthropic.com
2. Click the extension icon in Chrome toolbar
3. Enter your API key and click Save

Usage

1. Open Outlook in your browser (outlook.office.com, outlook.live.com)
2. Compose a new email
3. Paste an image (screenshot, copied image, etc.)
4. If the image doesn't already have alt text, a modal will appear with AI-generated alt text
5. Edit if needed and click "Apply Alt Text"

Supported Outlook Domains

• outlook.office.com
• outlook.office365.com
• outlook.live.com

Privacy & Security

• Your API key is stored locally in Chrome's secure storage
• Images are sent only to Claude API for analysis
• No data is stored on external servers
• No tracking or analytics

Cost

This extension uses the Claude API which has per-request costs. To optimize costs, the extension:

1. First uses Claude Haiku to classify image complexity (very low cost)
2. For simple images (photos, graphics, icons): uses Haiku for alt text generation (lower cost)
3. For complex images (charts, tables, text-heavy images): uses Sonnet for accurate transcription (higher cost)

Approximate costs per image:

• Simple images: ~$0.001-0.003 USD (Haiku classification + Haiku generation)
• Complex images: ~$0.01-0.05 USD (Haiku classification + Sonnet generation)

This conditional approach can reduce costs by 10-50x for simple images while maintaining quality for complex ones.

See Anthropic's pricing for current rates.

License

MIT License - see LICENSE file for details.

Contributing

Pull requests welcome! Please open an issue first to discuss proposed changes.