Alt Text Generator

Complete Guide to Alt Text for Images

What is Alt Text?

Alt text (alternative text) is a written description of an image's content and function. It serves as a text replacement for images when they cannot be displayed or accessed by users, particularly those using screen readers or other assistive technologies.

Why Alt Text is Critical for Your Website

Web Accessibility Compliance

Alt text is required under the Web Content Accessibility Guidelines (WCAG) 2.1 and Americans with Disabilities Act (ADA). Proper alt text ensures your website is accessible to the estimated 285 million visually impaired users worldwide.

SEO Benefits

Search engines cannot "see" images but can read alt text. Well-written alt text helps your images rank in Google Image search, which accounts for 22.6% of all web searches. Images with descriptive alt text are 2.5x more likely to appear in search results.

User Experience Enhancement

Alt text displays when images fail to load due to slow internet connections or technical issues, providing context to users regardless of their browsing conditions.

Alt Text Writing Best Practices

Character Limit Guidelines

Keep alt text under 125 characters. Screen readers typically cut off longer descriptions, and search engines may truncate longer text. Aim for 50-100 characters for optimal performance.

Content Structure

• Start with the main subject: Identify the primary focus first
• Add context: Include relevant background or setting information
• Mention important details: Colors, expressions, actions, or text in images
• Skip obvious elements: Don't state "image of" or "picture showing"

Language and Tone

Use clear, concise language that matches your website's tone. Avoid flowery descriptions or unnecessary adjectives. Focus on functional information that helps users understand the image's purpose and content.

Alt Text for Different Image Types

Photographs

Describe the main subject, setting, and any relevant actions or emotions. Include important visual details that contribute to the image's meaning or purpose.

Example: "Smiling woman in business suit presenting to colleagues in modern conference room"

Graphics and Illustrations

Focus on the graphic's message or function rather than artistic details. Explain what information the graphic conveys to viewers.

Example: "Flowchart showing customer journey from awareness to purchase"

Charts and Data Visualizations

Summarize the data's key findings or trends. For complex data, consider providing a longer description in the surrounding text or a data table alternative.

Example: "Line chart showing 40% increase in mobile traffic from 2020 to 2024"

Product Images

Include the product name, key features, colors, and any distinguishing characteristics that would influence a purchasing decision.

Example: "Red leather handbag with gold hardware and adjustable shoulder strap"

Screenshots

Describe what application or interface is shown and highlight the specific features or actions being demonstrated.

Example: "Email dashboard showing inbox with unread message notifications"

Technical Implementation

HTML Implementation

Add alt text using the alt attribute in img tags:

<img src="image.jpg" alt="Your descriptive alt text here">

Content Management Systems

Most CMS platforms provide alt text fields when uploading images:

• WordPress: "Alternative Text" field in Media Library
• Drupal: "Alternative text" field in image upload
• Shopify: "Alt text" option in product image settings
• Squarespace: "Alt Text" field in image block settings

Social Media Platforms

• Facebook: Click "Edit" on uploaded image → "Alternative Text"
• Twitter: Click "+ALT" when composing tweet with image
• Instagram: "Advanced Settings" → "Write Alt Text"
• LinkedIn: "Alt text" option appears when uploading images

Common Alt Text Mistakes to Avoid

Redundant Phrases

Avoid starting alt text with "image of," "picture of," or "graphic showing" as screen readers already announce that the element is an image.

Keyword Stuffing

While alt text can include relevant keywords for SEO, avoid cramming multiple keywords unnaturally. Focus on accurate, helpful descriptions first.

Leaving Alt Text Empty

Empty alt attributes (alt="") should only be used for purely decorative images that don't convey important information. Most images serve some functional purpose and need descriptions.

Being Too Verbose

Overly long descriptions can overwhelm screen reader users. Focus on essential information and context rather than every visual detail.

Alt Text for E-commerce

Product Photography

E-commerce alt text should help customers make purchasing decisions. Include:

• Product name and model/style
• Color and material
• Key features or functions
• Size or scale context

Lifestyle and Context Images

For images showing products in use, describe both the product and how it's being used:

Example: "Woman wearing blue yoga mat carrying strap while walking to outdoor class"

Testing and Quality Assurance

Screen Reader Testing

Test your alt text with actual screen readers like NVDA (free), JAWS, or VoiceOver (Mac/iOS) to ensure descriptions sound natural and provide useful information.

Automated Accessibility Tools

• WAVE: Web accessibility evaluation tool
• axe: Browser extension for accessibility testing
• Lighthouse: Built into Chrome DevTools
• Color Oracle: Color blindness simulator

Manual Review Process

Regularly audit your images for missing or inadequate alt text. Consider creating a content style guide that includes alt text standards for your organization.

Alt Text and SEO Strategy

Keyword Integration

Naturally incorporate target keywords when they accurately describe the image content. Don't force keywords that don't match the visual elements.

Image SEO Best Practices

• Use descriptive file names (not IMG_1234.jpg)
• Optimize image file sizes for faster loading
• Choose appropriate image formats (WebP, JPEG, PNG)
• Include images in your XML sitemap
• Add structured data markup when relevant

Legal and Compliance Considerations

ADA Compliance

The Americans with Disabilities Act requires digital accessibility for businesses open to the public. Proper alt text is essential for ADA compliance and avoiding potential lawsuits.

WCAG Guidelines

Follow WCAG 2.1 Level AA guidelines, which require:

• Meaningful alt text for all informative images
• Empty alt attributes for decorative images
• Alternative text that doesn't exceed 125 characters
• Context-appropriate descriptions

Future of Image Accessibility

AI-Generated Alt Text

While AI tools can generate basic alt text, human review remains essential for context, accuracy, and brand voice consistency. Use AI as a starting point, not a complete solution.

Voice Search Optimization

As voice search grows, alt text that uses natural language patterns will become increasingly important for discoverability.

Measuring Alt Text Effectiveness

Analytics and Metrics

• Image Search Traffic: Monitor traffic from Google Images
• Accessibility Scores: Use tools like Lighthouse
• User Feedback: Collect input from users with disabilities
• Bounce Rate: Track if proper alt text improves engagement

Continuous Improvement

Regularly review and update alt text based on user feedback, changing SEO landscapes, and evolving accessibility standards.

Frequently Asked Questions

Should decorative images have alt text?

Purely decorative images should have empty alt attributes (alt="") to indicate to screen readers that they can be safely ignored. However, if an image adds any context or meaning, it should have descriptive alt text.

How do I handle complex images like infographics?

For complex images, provide a brief alt text summary and include a detailed description in the surrounding text or a linked alternative format. Consider using the longdesc attribute or ARIA-describedby for extended descriptions.

Can I use the same alt text for similar images?

Each image should have unique alt text that describes its specific content and context. Even similar images may serve different purposes or appear in different contexts.

How often should I update alt text?

Review alt text when updating content, changing SEO strategies, or receiving accessibility feedback. At minimum, conduct an annual audit of all image alt text.