Duolingo ABC teaches reading through phonics, letter tracing, sight words, and short stories - same game-like approach as regular Duolingo. Ages 3-6. Completely free, no ads, no subscription. Hundreds of bite-sized lessons that kids actually want to repeat. From the makers of the world's most popular language app.

If your kid can hold a phone, they can start learning letters. Duolingo ABC breaks reading into tiny, game-like lessons - the same addictive loop that makes regular Duolingo work for adults.
The curriculum covers phonics (letter sounds), letter recognition and tracing, sight words, decodable stories, and reading comprehension. Lessons are 2-3 minutes each. Kids earn rewards, unlock new levels, and actually ask to play it again. That's the Duolingo magic.
Ages 3-6. Completely free - no ads, no premium tier, no in-app purchases. Duolingo funds this through their main language learning app.
Compared to Khan Academy Kids (also free, ages 2-8), Duolingo ABC is laser-focused on reading only. Khan Academy covers reading, math, and social-emotional learning. If your kid needs help specifically with letters and phonics, Duolingo ABC is more focused. If you want a broader early learning app, Khan Academy Kids covers more ground.
Compared to Endless Alphabet (vocabulary through puzzles), Duolingo ABC is more structured and curriculum-driven. Endless Alphabet is more playful and open-ended.
The downside: it only teaches reading. No math, no science, no social skills. That's by design - it does one thing well. But you'll need other apps for everything else.
Available on iOS and Android. Works offline for most lessons once downloaded.