Quick answer: For primary / lower-secondary (ages 9-14), AI Quest + BBC Bitesize AI is the strongest free / low-cost combo in 2026. For upper-secondary (14-18), AI Quest + Elements of AI works well. For schools with dedicated CS teachers, Code.org AI adds depth at the cost of installation overhead. Commercial curricula (IBM SkillsBuild, Microsoft Learn for Educators) remain valuable for structured CPD but are heavier than most classrooms need.

Six jobs-to-be-done

Conceptual understanding of what AI is and isn't.
Hands-on practice with actual AI tools, supervised.
Critical evaluation — bias, hallucination, reliability.
Ethical framing — consent, privacy, EU AI Act basics.
Engagement — will students still be learning at week 6?
Teacher-load — can a non-specialist teacher deliver it?

Options at a glance

AI Quest (Gera)

Free to play; gamified progression through 40+ levels. Covers LLMs, tokens, prompts, hallucination, evaluation. Strong on engagement and retention. Ages 12-18 (and curious adults). Teacher pack available.

Elements of AI (Helsinki / Reaktor)

Free, university-backed, 6-module course. Strongest conceptual grounding on the list. Heavier reading-load; best for 15+.

Code.org AI

Free, project-driven, excellent for schools already using Code.org. Needs a CS teacher to deliver effectively.

BBC Bitesize AI

Free, UK-curriculum-aligned snippets. Light touch; good scaffolding before AI Quest.

Common Sense AI

Free, strong on digital-citizenship framing, weaker on technical depth. Good ethics companion.

Commercial curricula (IBM, Microsoft, Google)

Free to schools but require teacher CPD investment. Better for teacher training than classroom delivery.

School-size decision matrix

Primary (ages 9-11): BBC Bitesize + AI Quest first 10 levels.
Lower secondary (11-14): AI Quest full run + Common Sense AI ethics.
Upper secondary (14-18): AI Quest + Elements of AI.
Specialist CS stream: add Code.org AI or Kaggle Learn.

Budget bands

Free tier (recommended): AI Quest + any free companion.
Small paid tier (< £500/yr): teacher pack + printed workbook.
Whole-school licence (£500-£2,000/yr): commercial curriculum + CPD.

AI Literacy Curriculum Buyer's Guide for Schools (2026)