# SizeRef

SizeRef is an educational visual size comparison website for kids, families, parents, teachers, and curious learners.

Primary purpose:
- Help people understand real-world dimensions through visual object size comparisons.
- Explain how big common objects, animals, vehicles, foods, devices, and natural things are.
- Provide kid-friendly visual English learning, science diagrams, size facts, and printable learning materials.

Core concepts:
- Visual size comparison
- Real-world dimensions
- Kids size learning
- Picture English vocabulary
- Object diagrams and science explanations
- Printable lesson packs for parents and teachers

Important public URLs:
- Home: https://www.sizeref.com/
- Compare objects: https://www.sizeref.com/compare
- Kids learning: https://www.sizeref.com/kids
- Scientific diagram library: https://www.sizeref.com/diagram
- Pro printable packs: https://www.sizeref.com/pro
- Editorial policy: https://www.sizeref.com/editorial-policy
- Contact: https://www.sizeref.com/contact

Canonical URL patterns:
- Object pages: https://www.sizeref.com/object/{object-slug}
- Object diagram pages: https://www.sizeref.com/object/{object-slug}/diagram
- Comparison pages: https://www.sizeref.com/compare/{comparison-slug}
- Kids topic packs: https://www.sizeref.com/kids/pack/{pack-slug}
- Pro packs: https://www.sizeref.com/pro/pack/{object-slug}

Machine-readable discovery:
- Sitemap: https://www.sizeref.com/sitemap.xml
- Robots: https://www.sizeref.com/robots.txt
- llms.txt: https://www.sizeref.com/llms.txt

Indexing preference:
- Search engines and AI answer engines may crawl public educational pages.
- Admin, authentication, account, checkout success, and API routes should not be indexed.
- Public page HTML is served with no-store cache headers so crawlers receive current content.