Claude SEO is an open-source Claude Code plugin that runs specialized agents and skills to audit websites across technical SEO, content quality, structured data, AI-search optimization, local and e-commerce SEO, and international SEO. SEO practitioners use it to produce prioritized recommendations based on primary-source guidance, with optional extensions for external data and crawling.
Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/AgriciDaniel/claude-seonpx agentmods add skills/agricidaniel/claude-seo/seo-imagesWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/agricidaniel/claude-seo/seo-images)<a href="https://agentmods.dev/skills/agricidaniel/claude-seo/seo-images"><img src="https://agentmods.dev/badge/skills/agricidaniel/claude-seo/seo-images/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/agricidaniel/claude-seo/seo-images"><img src="https://agentmods.dev/badge/skills/agricidaniel/claude-seo/seo-images.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk warn
- NVIDIA SkillSpector warn
SkillSpector: 4 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Privilege Escalation · line 237 Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
- medium Privilege Escalation · line 238 Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
- medium Privilege Escalation · line 432 Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
- medium Privilege Escalation · line 433 Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00108 | $0.04171 |
| Opus 5 | $0.00054 | $0.02086 |
| Sonnet 5 | $0.00022 | $0.00834 |
| Haiku 4.5 | $0.00011 | $0.00417 |
Grade A, and why
seo-images scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 435 lines — stays where its author put it; the contents beside it link to each section on GitHub.
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
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.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 11d ago First seen · 435 lines · 108 tokens per session scan A 00c1e22f2d82
seo-images is a skill published in the GitHub repository AgriciDaniel/claude-seo (16,692 stars, last pushed 16d ago), licensed MIT. It adds 108 tokens to every session and 4,171 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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