Image Optimization Analysis
Checks
Alt Text
- Present on all
<img> elements (except decorative: role="presentation")
- Descriptive: describes the image content, not "image.jpg" or "photo"
- Includes relevant keywords where natural, not keyword-stuffed
- Length: 10-125 characters
Good examples:
- "Professional plumber repairing kitchen sink faucet"
- "Red 2024 Toyota Camry sedan front view"
- "Team meeting in modern office conference room"
Bad examples:
- "image.jpg" (filename, not description)
- "plumber plumbing plumber services" (keyword stuffing)
- "Click here" (not descriptive)
File Size
Tiered thresholds by image category:
| Image Category |
Target |
Warning |
Critical |
| Thumbnails |
< 50KB |
> 100KB |
> 200KB |
| Content images |
< 100KB |
> 200KB |
> 500KB |
| Hero/banner images |
< 200KB |
> 300KB |
> 700KB |
Recommend compression to target thresholds where possible without quality loss.
Format
| Format |
Browser Support |
Use Case |
| WebP |
97%+ |
Default recommendation |
| AVIF |
92%+ |
Best compression, newer |
| JPEG |
100% |
Fallback for photos |
| PNG |
100% |
Graphics with transparency |
| SVG |
100% |
Icons, logos, illustrations |
Recommend WebP/AVIF over JPEG/PNG. Check for <picture> element with format fallbacks.
Recommended <picture> Element Pattern
Use progressive enhancement with the most efficient format first:
<picture>
<source srcset="image.avif" type="image/avif">
<source srcset="image.webp" type="image/webp">
<img src="image.jpg" alt="Descriptive alt text" width="800" height="600" loading="lazy" decoding="async">
</picture>
The browser will use the first supported format. Current browser support: AVIF 93.8%, WebP 95.3%.
JPEG XL: Emerging Format
In November 2025, Google's Chromium team reversed its 2022 decision and announced it will restore JPEG XL support in Chrome using a Rust-based decoder. The implementation is feature-complete but not yet in Chrome stable. JPEG XL offers lossless JPEG recompression (~20% savings with zero quality loss) and competitive lossy compression. Not yet practical for web deployment, but worth monitoring for future adoption.
Responsive Images
srcset attribute for multiple sizessizes attribute matching layout breakpoints- Appropriate resolution for device pixel ratios
<img
src="image-800.jpg"
srcset="image-400.jpg 400w, image-800.jpg 800w, image-1200.jpg 1200w"
sizes="(max-width: 600px) 400px, (max-width: 1200px) 800px, 1200px"
alt="Description"
>
Lazy Loading
loading="lazy" on below-fold images- Do NOT lazy-load above-fold/hero images (hurts LCP)
- Check for native vs JavaScript-based lazy loading
<img src="photo.jpg" loading="lazy" alt="Description">
<img src="hero.jpg" alt="Hero image">
fetchpriority="high" for LCP Images
Add fetchpriority="high" to your hero/LCP image to prioritize its download in the browser's network queue:
<img src="hero.webp" fetchpriority="high" alt="Hero image description" width="1200" height="630">
Critical: Do NOT lazy-load above-the-fold/LCP images. Using loading="lazy" on LCP images directly harms LCP scores. Reserve loading="lazy" for below-the-fold images only.
decoding="async" for Non-LCP Images
Add decoding="async" to non-LCP images to prevent image decoding from blocking the main thread:
<img src="photo.webp" alt="Description" width="600" height="400" loading="lazy" decoding="async">
CLS Prevention
width and height attributes set on all <img> elementsaspect-ratio CSS as alternative- Flag images without dimensions
<img src="photo.jpg" width="800" height="600" alt="Description">
<img src="photo.jpg" style="aspect-ratio: 4/3" alt="Description">
<img src="photo.jpg" alt="Description">
File Names
- Descriptive:
blue-running-shoes.webp not IMG_1234.jpg
- Hyphenated, lowercase, no special characters
- Include relevant keywords
CDN Usage
- Check if images served from CDN (different domain, CDN headers)
- Recommend CDN for image-heavy sites
- Check for edge caching headers
Output
Image Audit Summary
| Metric |
Status |
Count |
| Total Images |
- |
XX |
| Missing Alt Text |
❌ |
XX |
| Oversized (>200KB) |
⚠️ |
XX |
| Wrong Format |
⚠️ |
XX |
| No Dimensions |
⚠️ |
XX |
| Not Lazy Loaded |
⚠️ |
XX |
Prioritized Optimization List
Sorted by file size impact (largest savings first):
| Image |
Current Size |
Format |
Issues |
Est. Savings |
| ... |
... |
... |
... |
... |
Recommendations
- Convert X images to WebP format (est. XX KB savings)
- Add alt text to X images
- Add dimensions to X images
- Enable lazy loading on X below-fold images
- Compress X oversized images
Image SERP Analysis
When DataForSEO MCP is available, enhance the image audit with competitive data.
/seo images serp <keyword>
Cross-reference on-page images with Google Images SERP rankings.
Workflow:
- Fetch Google Images results via
serp_google_images_live_advanced (depth=100)
- Extract: top domains, image types, alt text patterns
- Output competitor image SERP landscape
Output:
| Rank |
Domain |
Title/Alt |
Image URL |
Page URL |
| 1 |
example.com |
"Blue running shoes..." |
.../shoes.webp |
/products/... |
Analysis includes:
- Domain dominance: which sites own the most image positions (top 10 by count)
- Alt text patterns: common title/alt patterns in top-ranking images
- Format distribution: WebP vs JPEG vs PNG in top results
- Opportunity score: keywords where you have page rankings but no image presence
If DataForSEO MCP is not available, inform user and suggest installing the extension.
Image File Optimization
Optimize image files for SEO: format conversion, metadata injection, compression.
/seo images optimize <path>
Optimize image file(s) for web and SEO. Converts to WebP/AVIF, injects IPTC
metadata, compresses, and generates responsive variants.
Tools used (in order of preference):
exiftool -- EXIF/IPTC/XMP read/write (install: sudo apt install libimage-exiftool-perl)cwebp -- WebP conversion (install: sudo apt install webp)- ImageMagick
convert -- Format conversion, resizing (pre-installed on most systems)
- FFmpeg -- Fallback for format conversion (pre-installed)
Before running: Check which tools are available with which exiftool cwebp convert ffmpeg.
Format Conversion
Convert images to modern formats with metadata preservation:
cwebp -q 82 -metadata all input.jpg -o output.webp
convert input.jpg -quality 82 output.webp
ffmpeg -i input.jpg -c:v libaom-av1 -crf 30 -still-picture 1 output.avif
convert input.jpg -resize 400x -quality 82 image-400.webp
convert input.jpg -resize 800x -quality 82 image-800.webp
convert input.jpg -resize 1200x -quality 82 image-1200.webp
Metadata Injection (IPTC for Google Rich Results)
Google Images displays IPTC Creator, Credit Line, and Copyright in search results.
This is NOT a ranking factor but improves rich result display and brand attribution.
With exiftool (preferred):
exiftool image.jpg
exiftool \
-IPTC:ObjectName="Product Photo Description" \
-IPTC:Caption-Abstract="Detailed image description" \
-IPTC:By-line="Brand Name Photography" \
-IPTC:Credit
