seo-images

Image optimization analysis for SEO and performance. Checks alt text, file sizes, formats, responsive images, lazy loading, CLS prevention, image SERP rankings…

INSTALLATION
npx skills add https://github.com/agricidaniel/claude-seo --skill seo-images
Run in your project or agent environment. Adjust flags if your CLI version differs.

SKILL.md

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 CategoryTargetWarningCritical
Thumbnails100KB> 200KB
Content images200KB> 500KB
Hero/banner images300KB> 700KB

Recommend compression to target thresholds where possible without quality loss.

Format

FormatBrowser SupportUse Case
WebP97%+Default recommendation
AVIF92%+Best compression, newer
JPEG100%Fallback for photos
PNG100%Graphics with transparency
SVG100%Icons, logos, illustrations

Recommend WebP/AVIF over JPEG/PNG. Check for <picture> element with format fallbacks.

#### Recommended

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

Third-party reporting and Wikipedia describe a Rust-based JPEG XL decoder as shipped in Chrome 145 stable (2026-02-10) behind the chrome://flags/#enable-jxl-image-format flag, not enabled by default; no Google-owned confirmation was retrieved in the fact pack. Because default support is not confirmed, it is not yet practical for production web delivery. Keep serving AVIF/WebP with JPEG fallback and monitor.

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_methodSignal detectedCommon stack
nativeloading="lazy" HTML attributeModern browsers, plain HTML
perfmattersdata-perfmatters-src/-srcset OR class perfmatters-lazyWordPress + Perfmatters plugin
ewwwdata-ewww-src / data-eio OR class lazyload-eioWordPress + EWWW Image Optimizer
js-genericdata-src / data-lazy-src / data-original / data-srcset OR class lazyload/lazyloaded/lazyLazysizes, vanilla-lazyload, jQuery plugins
noneNeither attribute nor class signalPage 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

MetricStatusCount
Total Images-XX
Missing Alt TextXX
Oversized (>200KB)⚠️XX
Wrong Format⚠️XX
No Dimensions⚠️XX
Not Lazy Loaded⚠️XX

Prioritized Optimization List

Sorted by file size impact (largest savings first):

ImageCurrent SizeFormatIssuesEst. 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

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:

RankDomainTitle/AltImage URLPage URL
1example.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

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 Images Display)

Google Images displays IPTC Creator, Credit Line, and Copyright in search results.

This is NOT a ranking factor but can improve Google Images 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

Note: 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 (Merchant Center AI-generated content policy):

https://support.google.com/merchants/answer/14743464

(the ai-optimization-guide does not document DigitalSourceType/IPTC/Merchant labeling.)

Audit command:

# Audit a directory for the IPTC label (counts: missing, ai, captured, etc.)

claude-seo run iptc_ai_label.py audit ./images/ --json

# Audit a single image

claude-seo run iptc_ai_label.py audit ./hero.webp --json

# Inject the AI label into an image

claude-seo run iptc_ai_label.py inject ./ai-hero.webp \

    --source-type trainedAlgorithmicMedia

# Other vocabulary values:

#   compositeSynthetic               (mix of captured + AI elements)

#   algorithmicMedia                 (created purely by algorithm, NOT from sampled training data)

#   compositeWithTrainedAlgorithmicMedia (e.g. AI inpainting/outpainting over real media)

#   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

Google extracts these IPTC DigitalSourceType values:

  • trainedAlgorithmicMedia: fully AI-generated (use this for diffusion-model

product imagery)

  • compositeSynthetic: mixes captured + AI-generated elements
  • algorithmicMedia: created purely by an algorithm, not from sampled

training data

  • compositeWithTrainedAlgorithmicMedia: composite of trained algorithmic

media + other media (e.g. AI inpainting/outpainting over a real photo)

  • digitalCapture: fully captured photograph (note: digitalCapture is not

on Google's extracted-values list, but is a valid IPTC value)

Provenance signals (consumer-facing): SynthID watermarks and C2PA

Content Credentials are emerging signals for AI media identification. Treat

product-surface coverage as subject to change unless verified from a current

Google-owned source.

This is detection/transparency, not an extra required Merchant feed field

beyond IPTC DigitalSourceType.

Licensable images: to earn the Licensable badge, supply EITHER structured

data (ImageObject with the license property + acquireLicensePage for the

"Get this image" link) OR embedded IPTC photo metadata (Licensor URL / Web

Statement of Rights). Cross-link seo-schema for the ImageObject markup.

Discovery note: image discovery now includes visual search fan-out

across Lens / AI Mode / Circle to Search (Gemini multimodal scene/object

understanding), so images surface via scene, objects, and materials, not alt

text alone. No new published image-SEO lever yet; keep descriptive alt text +

clean structured data.

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

FactorImpactWhere to Set
Alt textCRITICAL (ranking)HTML
FilenameHIGH (ranking)File system (descriptive, hyphenated)
Page contextHIGH (ranking)Surrounding HTML content
File size/speedMEDIUM (indirect via CWV)Compression + format conversion
IPTC Creator/CopyrightLOW (display only)Image file metadata
EXIF camera dataNONEIrrelevant for SEO
IPTC KeywordsNONEGoogle ignores these

Error Handling

ScenarioAction
URL unreachableReport connection error with status code. Suggest verifying URL and checking if site requires authentication.
No images found on pageReport that no elements were detected. Suggest checking if images are loaded via JavaScript or CSS background-image.
Images behind CDN or authenticationNote 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 installedFall back to ImageMagick for metadata. Recommend: sudo apt install libimage-exiftool-perl
cwebp not installedFall back to ImageMagick or FFmpeg for WebP conversion. Recommend: sudo apt install webp
DataForSEO MCP not availableSkip Image SERP Analysis section. Note extension is not installed.
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