Brilliant vs Key2Stats

Brilliant is an interactive STEM learning service with courses in math, coding, data science, science, technology, and AI. Learners work through problems, explore visual models, and receive immediate feedback. Most courses include Koji, a digital tutor that guides learners through reasoning step by step. Free accounts can access all courses but are limited to two lessons per day in sequence, see occasional ads, and receive only a limited Koji preview. Premium adds unlimited lessons and practice, the option to jump to any lesson, an ad-free experience, and full Koji access. Individual Premium is listed at $20 a year, billed as one payment and renewed annually; Family Premium is $40 a year, also billed as one payment and renewed annually, with six seats included. Eligible K–12 teachers and their students may receive free Premium through an application-reviewed educator program. That program supports Google Classroom roster syncing and lesson sharing. Its reports show lesson completion, time spent, course progress, and completion dates, but not answer-level correctness or formal grades. Brilliant runs on Android, iOS, and web, and lessons require an internet connection and cannot be downloaded.

Key2Stats has no write-up on Specifiction yet; its figures are above.