Keywords Social media Age restrictions Australia Evaluation Policy Mental health Youth Adolescent Wellbeing Safety by design Introduction In December 2025, Australia implemented a world-first social media age-restriction policy aimed at preventing individuals under 16 years from holding accounts on major social media platforms, including Facebook, Instagram, Snapchat, TikTok, X, and YouTube.1 Platforms are now legally required to adopt age-verification systems, with fines of up to AUD$49.5...