seo-images

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 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.

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.