SAPIRO and Duolingo are both learning apps, but on different territory. Duolingo teaches languages. SAPIRO develops general knowledge. Here is where they overlap and diverge.
What you learn
Duolingo. Language learning: English, Spanish, German, Italian, Mandarin, etc. Over 40 languages available. Linguistic skill: vocabulary, grammar, conjugation, listening, expression.
SAPIRO. General knowledge learning: geography (197 countries, flags, capitals), history (500+ figures), art (553 works), nature (600 animal species). Factual and cultural skill.
Method
Duolingo. Heavy gamification: short lessons, badges, hearts, streaks, friend leaderboards. Very addictive. Streak pressure.
SAPIRO. Pure quiz format with educational explanation. More pedagogical, less addictive. No aggressive notifications. See our article on gamification of learning.
Free tier
Duolingo. Free with ads and heart limit (long recharge after errors). Super Duolingo ($8-14/month) removes that.
SAPIRO. Free with all features, no ads, no limits. Sapiro+ ($1.99/month or $39.99 lifetime) for extended features.
Advertising
Duolingo. Lots of ads in the free version. Can be heavy.
SAPIRO. Zero ads. See our article on best ad-free educational apps.
Data collection
Duolingo. Significant data collection for personalization and advertising. Mandatory account.
SAPIRO. No data collection. No mandatory account. See our article on quiz apps without data collection.
Target audience
Duolingo. Language learners, all levels. Adults wanting to travel, students alongside their classes, professionals.
SAPIRO. Curious of all ages. Families, students, exam candidates, adults seeking general culture.
When to use each
Duolingo if you want to learn a language from scratch or consolidate. Progressive, structured, playful but repetitive.
SAPIRO if you want to develop your general knowledge (countries, history, art, nature). Educational quiz learning.
Can they coexist?
Yes. Many users combine both: 15 minutes of language in the morning with Duolingo, 15 minutes of general knowledge in the evening with SAPIRO. They are complementary skills, not competitors.
Worth reading: best general knowledge quiz apps.