Image Accessibility SEO Rule

Verify that all images are accessible by checking src attributes, HTTP status codes, content types, and file sizes

What This Rule Checks

Validates every image is accessible: checks for missing src attributes, verifies HTTP status codes, validates content types are image/*, detects very large files (>5MB), and handles data URIs and network errors.

Why It Matters for SEO & GEO

Broken or inaccessible images create poor user experiences and waste crawl budget. Search engines may penalize pages with many broken resources.

How to Fix

Ensure all image src URLs are valid and return HTTP 200. Use proper image content types. Keep images under 5MB. Fix DNS errors and broken image links promptly.

Examples

Bad

<img src="https://broken-link.com/missing.jpg" alt="Photo">

Good

<img src="https://cdn.example.com/photo.webp" alt="Team meeting in progress">

How VibeLinter Checks Image Accessibility

VibeLinter’s images/accessibility rule performs these checks on every image:

Missing src — Errors when an image tag has no src attribute
Data URI validation — Checks that data URIs use the data:image/* format
HTTP status check — Makes HEAD requests to verify images return a successful HTTP status (under 400)
Content type validation — Warns when the resource at the image URL does not return an image/* content type
File size check — Warns when images exceed 5MB, which may cause accessibility and loading issues
Network error handling — Provides specific error messages for DNS failures (ENOTFOUND), connection refused (ECONNREFUSED), and timeouts (>10 seconds)
URL validation — Reports malformed image URLs that cannot be parsed

Configuration

// vibelinter.config.cjs
module.exports = {
  rules: {
    'images/accessibility': {
      enabled: true,
      severity: 'error'
    }
  }
}

SEO Impact

Image accessibility affects:

Crawl efficiency — Broken images waste crawl budget and signal poor site maintenance
User experience — Broken images create visual holes and hurt engagement metrics
Search engine trust — Pages with many broken resources may receive lower quality scores
GEO (Generative Engine Optimization) — AI models evaluating content quality consider broken resources as negative signals; accessible, well-maintained images improve the likelihood of being cited in AI-generated answers