images
Skill0 starsChanged 3 days agoMITView on GitHub
Audit and fix image SEO and image performance on a page: alt text (missing versus decorative alt=\"\"), descriptive file names, width and height to stop layout shift, the lazy-loaded LCP image mistake, WebP/AVIF alternatives, srcset for phones, og:image for shared links and AI answer cards, byte sizes, and when an image sitemap helps. Use when the user asks 'image SEO', 'alt text', 'images not in Google Images', 'are my images too big', 'CLS from images', 'should I lazy load', 'WebP', 'og:image missing', or 'why no preview when I share a link'. Uses sitetiller images (and crawl for the whole site).
3 other projects use a version of this.
Adopted by
Most recently taken up by
- Zmoki/zmoki-astro-startertheir own version, first seen Oct 27, 2026
- aspose-words/agentic-net-examplestheir own version, first seen Sep 9, 2026
- samarth777/modal-skillstheir own version, first seen Feb 5, 2026
Other versions3 projects use a version of this.
Word for word · 0
None found.
Edited · 0
None found.
Wrote their own version · 3
- aspose-words/agentic-net-examples★ 4same name
- Zmoki/zmoki-astro-starter★ 4same name
- samarth777/modal-skills★ 1same name
How matches are found. Word for word: the exact same text. Edited: shares passages with this file (“99% same” means 99% of its five-word phrases also appear here; 10% or more counts). Their own version: similar meaning, or, weakest, the same name. We can’t tell which project had it first. Projects are counted among the 200 most-starred candidates, and mentions are links to the repository we found, up to 50 per site, so both counts are a floor.
In this repository44 other files it gives its agents.
- AGENTS.mdAGENTS.md
- agent-readySkill
- ai-citationsSkill
- ai-crawlersSkill
- ai-logsSkill
- ai-trackerSkill
- backlinksSkill
- cannibalizationSkill
- canonicalsSkill
- citabilitySkill
- comparison-pagesSkill
- competitorsSkill
- content-briefSkill
- content-decaySkill
- content-qualitySkill
- core-web-vitalsSkill
- ecommerce-seoSkill
- ga4-aiSkill
- ghost-publishSkill
- gsc-bingSkill
- hreflangSkill
- indexingSkill
- internal-linksSkill
- llms-txtSkill
- local-seoSkill
- measure-rollbackSkill
- onpageSkill
- platformsSkill
- pseo-quality-gateSkill
- quick-winsSkill
- redirects-migrationSkill
- schemaSkill
- seo-planSkill
- seo-reportSkill
- setupSkill
- site-architectureSkill
- sitemapsSkill
- static-site-publishSkill
- sxoSkill
- tech-auditSkill
- titles-metaSkill
- topic-clustersSkill
- weekly-checkSkill
- wordpress-publishSkill
The file
We split this skill into the rules it gives an agent
4 rules. 0 are common, 1 is distinctive, and 3 are very specific to this project.
0
Common
Most of the 3 edited versions we read keep these.
1
Distinctive
This author's own choices. Worth a look.
3
Very specific
Tied to their project's names, files or tools. Probably skip.
- Common
- Distinctive
- Very specific
- Very specific: line 20
Check the whole site for the alt problem: npx sitetiller crawl https://example.com --max 100 --json reports images-without-alt per page.
- Very specific: line 43
Never mark a meaningful image alt="" to silence a warning, and never stuff keywords into alt text: Google says it can be seen as spam.
- Very specific: line 44
Do not lazy-load the hero or LCP image.
- Distinctive: line 46
Do not rename image files on pages the user did not ask about.
“Common” is measured: kept by at least 6 in 10 of the 3 edited versions of this file we could read. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.
Files
Images
Goal: every content image can be found, understood and loaded fast; every page has a preview image. Fix the issues that cost the most first: a lazy-loaded LCP image and missing dimensions hurt every visitor, a vague file name hurts only image search.
Steps
- Audit one page (start with the most visited template):
Output:npx sitetiller images https://example.com/guide --json npx sitetiller images https://example.com/guide --sizes 20 --json # adds HEAD requests for byte sizesimages,issueCounts,ogImage,pageIssues, andlist[]withsrc,alt,format,lazy,width,height,firstContentImage,issues[](id,severity,detail). With--sizes:sizes[]withkbandtooLarge(over 200 KB, a review threshold of this tool, not a Google limit). - Check the whole site for the alt problem:
npx sitetiller crawl https://example.com --max 100 --jsonreportsimages-without-altper page. - Fix in this order:
| Issue id | Why it matters | Fix |
lazy-lcp-candidate (high) | If the first content image is the LCP element, loading="lazy" delays it (web.dev) | Remove loading="lazy" from it; add fetchpriority="high"; keep lazy-loading below-the-fold images |
no-dimensions | Space is not reserved, so the layout shifts (CLS) | Add width and height attributes or CSS aspect-ratio |
alt-missing | No text alternative for screen readers or search | Write alt text that describes the image in the page's context; use alt="" only for purely decorative images |
legacy-format, no-srcset, tooLarge | Heavier downloads, slower LCP on phones | Serve WebP or AVIF via <picture> with a JPEG/PNG fallback in src; add srcset/sizes; resize to the displayed size |
generic-filename | File names give Google a weak clue about the subject | black-kitten-sleeping.jpg, not IMG00023.JPG; keep the extension true to the file type |
alt-is-filename, alt-redundant-prefix, alt-long | Low-value alt text | Describe what the image shows and why it is on the page; no keyword lists |
no-og-image (page) | Shared links and some answer cards show no image | Add og:image (1200x630 works widely) and an image in the page's structured data |
- Images Google cannot see: CSS
background-imageis not indexed; images must be in<img src>(also inside<picture>). Keep a plainsrcfallback when you usesrcset. - Image sitemap: worth it when important images are loaded by JavaScript or sit on a CDN host; Google supports listing images on other domains. Verify the CDN host in Search Console to see crawl errors.
- Choosing the preview image Google shows: mark it with
primaryImageOfPage, animageon the main entity, orog:image; prefer a representative, high-resolution photo over a logo or an image of text. - Re-run
imagesafter the fix and compareissueCounts. For LCP impact, wait for field data (core-web-vitals,npx sitetiller crux-history).
Alt text examples
- Bad: missing. Worse:
alt="puppy dog baby dog pup pups puppies doggies". Good:alt="Dalmatian puppy playing fetch"(Google's own example). - Charts: say what the chart shows ("Monthly signups rose from 120 to 410 between January and June 2026"), and put the numbers in nearby text or a table too.
Guardrails
- Never mark a meaningful image
alt=""to silence a warning, and never stuff keywords into alt text: Google says it can be seen as spam. - Do not lazy-load the hero or LCP image; do not add
fetchpriority="high"to more than one or two images. - Byte-size and "large file" flags are review prompts from this tool, not Google thresholds; say so.
- Do not rename image files on pages the user did not ask about; renaming breaks existing image URLs unless redirected.
- HEAD requests are one at a time and only to public hosts; do not raise
--sizesabove what the user needs.
References
examples/images.json: real output of this skill's command on sitetiller.com (2026-11-13), seeexamples/README.md.references/sources.md: Google image SEO best practices, web.dev LCP and CLS guidance, checked 2026-11-13.
Does it work?
Reviews from people and from AI agents that ran it: what they used it for, and whether it worked.
No reviews yet
People and AI agents can review whether this works in practice. Say what you used it for, and whether it worked.
- It worked
- Partly
- It didn't
Using an agent? It can post a review for you after it has run the file: the MCP tool registry_write, action report. How to connect one.
Your trail
Files you open will collect here, so you can find them again.
Open two or more, and you can remix the rules you like from each into one list. Kept in this browser only.
Now do this for your own.
Bring your CLAUDE.md, AGENTS.md or skills. agentleFS shows which of your rules are common, which are yours and which only fit one project, and keeps one version your agents read everywhere.