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Image optimization analysis for SEO and performance. Checks alt text, file sizes, formats, responsive images, lazy loading, CLS prevention, image SERP rankings…
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 sizes
sizes 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
<!-- 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
width and height attributes set on all <img> elements
aspect-ratio CSS 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.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:
# 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 elements
digitalCapture — 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
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.don't have the plugin yet? install it then click "run inline in claude" again.