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
srcsetattribute for multiple sizessizesattribute 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
<!-- Below fold - lazy load -->
<img src="photo.jpg" loading="lazy" alt="Description">
<!-- Above fold - eager load (default) -->
<img src="hero.jpg" alt="Hero image">
Detected lazy-loader methods (lazy_method field)
scripts/parse_html.py classifies each image's lazy-loading mechanism via the lazy_method field on every image entry. Five values:
lazy_method | Signal detected | Common stack |
|---|---|---|
native | loading="lazy" HTML attribute | Modern browsers, plain HTML |
perfmatters | data-perfmatters-src/-srcset OR class perfmatters-lazy | WordPress + Perfmatters plugin |
ewww | data-ewww-src / data-eio OR class lazyload-eio | WordPress + EWWW Image Optimizer |
js-generic | data-src / data-lazy-src / data-original / data-srcset OR class lazyload/lazyloaded/lazy | Lazysizes, vanilla-lazyload, jQuery plugins |
none | Neither attribute nor class signal | Page is not lazy-loading this image |
When auditing image SEO, report lazy_method alongside loading so users know whether their site is using a JS-driven lazy-loader (in which case the native loading="lazy" attribute is intentionally absent — that is not a regression).
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
widthandheightattributes set on all<img>elementsaspect-ratioCSS as alternative- Flag images without dimensions
<!-- Good - dimensions set -->
<img src="photo.jpg" width="800" height="600" alt="Description">
<!-- Good - CSS aspect ratio -->
<img src="photo.jpg" style="aspect-ratio: 4/3" alt="Description">
<!-- Bad - no dimensions -->
<img src="photo.jpg" alt="Description">
File Names
- Descriptive:
blue-running-shoes.webpnotIMG_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
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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.
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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:
# WebP (recommended default) - with metadata preserved
cwebp -q 82 -metadata all input.jpg -o output.webp
# WebP via ImageMagick (fallback if cwebp not installed)
convert input.jpg -quality 82 output.webp
# AVIF via FFmpeg (slower encode, best compression)
ffmpeg -i input.jpg -c:v libaom-av1 -crf 30 -still-picture 1 output.avif
# Responsive variants (400w, 800w, 1200w)
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):
# Read all metadata
exiftool image.jpg
# Inject IPTC + XMP metadata for Google Images rich results
exiftool \
-IPTC:ObjectName="Product Photo Description" \
-IPTC:Caption-Abstract="Detailed image description" \
-IPTC:By-line="Brand Name Photography" \
-IPTC:Credit="Brand Name" \
-IPTC:CopyrightNotice="Copyright 2026 Brand Name" \
-IPTC:Source="brandname.com" \
-XMP:Title="Product Photo Description" \
-XMP:Description="Detailed image description" \
-XMP:Creator="Brand Name Photography" \
-XMP:Rights="Copyright 2026 Brand Name" \
image.jpg
# Batch inject to all images in directory
exiftool -overwrite_original \
-IPTC:By-line="Brand Name" \
-IPTC:CopyrightNotice="Copyright 2026 Brand Name" \
*.jpg *.webp *.png
With ImageMagick (fallback):
identify -verbose image.jpg | head -50
convert input.jpg \
-set comment "Product Photo Description" \
-set IPTC:2:80 "Brand Name Photography" \
-set IPTC:2:116 "Copyright 2026 Brand Name" \
output.jpg
IMPORTANT: WebP supports EXIF and XMP but NOT IPTC natively. For WebP files, use XMP fields instead of IPTC. exiftool handles this conversion automatically.
AI-Generated Images: DigitalSourceType (Merchant Center requirement)
For product images produced by generative AI, Google Merchant Center requires IPTC DigitalSourceType: TrainedAlgorithmicMedia metadata. This is an operational policy requirement, not a ranking factor — feeds missing this label on AI-generated imagery can be disapproved.
Primary source: https://developers.google.com/search/docs/fundamentals/ai-optimization-guide (references the underlying Merchant Center policy on AI media labeling).
Audit command:
# Audit a directory for the IPTC label (counts: missing, ai, captured, etc.)
python3 scripts/iptc_ai_label.py audit ./images/ --json
# Audit a single image
python3 scripts/iptc_ai_label.py audit ./hero.webp --json
# Inject the AI label into an image
python3 scripts/iptc_ai_label.py inject ./ai-hero.webp \
--source-type trainedAlgorithmicMedia
# Other vocabulary values:
# compositeSynthetic (mix of captured + AI elements)
# digitalCapture (fully captured photograph)
Raw exiftool equivalents (for ad-hoc usage):
# Inject manually
exiftool \
-XMP-iptcExt:DigitalSourceType="https://cv.iptc.org/newscodes/digitalsourcetype/trainedAlgorithmicMedia" \
ai-generated-product.jpg
# Audit: find images missing the label across a directory
exiftool -if 'not $XMP-iptcExt:DigitalSourceType' \
-filename -DigitalSourceType *.jpg *.webp *.png
The IPTC vocabulary also defines:
trainedAlgorithmicMedia— fully AI-generated (use this for diffusion-model
product imagery)
compositeSynthetic— mixes captured + AI-generated elementsdigitalCapture— fully captured photograph (no AI element)
When /seo images optimize is run on AI-generated assets, prompt the user to confirm the source type and inject the matching IPTC value automatically.
For AI-generated product titles and descriptions, Google Merchant Center also requires the AI-generated text to be separately specified and labeled in the feed. This is enforced at the feed layer, not the page layer — flag this in cross-reference with seo-ecommerce.
Metadata Audit
# Quick audit with exiftool
exiftool -IPTC:all -XMP:all -EXIF:ImageDescription image.jpg
# Batch audit - find images missing IPTC Creator
exiftool -if 'not $IPTC:By-line' -filename *.jpg *.webp *.png
Full Optimization Pipeline
For maximum image SEO, run this pipeline on each image:
- Audit existing metadata:
exiftool -IPTC:all -XMP:all image.jpg - Inject IPTC/XMP metadata: Creator, Copyright, Description
- Convert to WebP:
cwebp -q 82 -metadata all image.jpg -o image.webp - Generate responsive variants: 400w, 800w, 1200w
- Verify metadata preserved:
exiftool image.webp - Generate
<picture>HTML: AVIF > WebP > JPEG fallback chain
What Matters vs What Doesn't for Google Images
| Factor | Impact | Where to Set |
|---|---|---|
| Alt text | CRITICAL (ranking) | HTML <img alt=""> |
| Filename | HIGH (ranking) | File system (descriptive, hyphenated) |
| Page context | HIGH (ranking) | Surrounding HTML content |
| File size/speed | MEDIUM (indirect via CWV) | Compression + format conversion |
| IPTC Creator/Copyright | LOW (display only) | Image file metadata |
| EXIF camera data | NONE | Irrelevant for SEO |
| IPTC Keywords | NONE | Google ignores these |
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Error Handling
| Scenario | Action |
|---|---|
| URL unreachable | Report connection error with status code. Suggest verifying URL and checking if site requires authentication. |
| No images found on page | Report that no <img> elements were detected. Suggest checking if images are loaded via JavaScript or CSS background-image. |
| Images behind CDN or authentication | Note that image files could not be directly accessed for size analysis. Report available metadata (alt text, dimensions, format from markup) and flag inaccessible resources. |
| exiftool not installed | Fall back to ImageMagick for metadata. Recommend: sudo apt install libimage-exiftool-perl |
| cwebp not installed | Fall back to ImageMagick or FFmpeg for WebP conversion. Recommend: sudo apt install webp |
| DataForSEO MCP not available | Skip Image SERP Analysis section. Note extension is not installed. |

