The short version

Duolingo is a general-purpose language app that covers dozens of languages. It's great for building a daily habit, learning basic phrases, and getting a feel for how Russian sounds. But when it comes to the things that make Russian hard - cases, conjugation, aspect pairs - it stays surface-level.

Slova does one thing: Russian vocabulary with grammar depth. Every word comes with its full paradigm. Exercises test real production (typing, not tapping). It's not trying to replace Duolingo - it picks up where Duolingo stops being useful.

Feature comparison

Feature Duolingo Slova
Case training Introduced implicitly All 6 cases, fill-in-the-blank drills
Declension tables Not available Full tables for every noun & adjective
Verb conjugation Shown in context Full conjugation tables + targeted drills
Aspect pairs Not explicitly taught Linked pairs with context sentences
Exercise format Mostly multiple choice Typing-based (production)
Vocabulary size Large course (~2000+ words) 530+ curated words (A1–B1)
Listening & speaking Audio exercises, speech recognition Text-based only (for now)
Gamification Streaks, XP, leagues, hearts Minimal - focused on learning
Spaced repetition Proprietary algorithm SM-2 with per-word scheduling
Custom word lists Fixed curriculum Add any word, exercises auto-generate
Price Free (with ads/hearts) or $7/mo Free
Languages 40+ languages Russian only

Where Duolingo wins

Let's be fair. Duolingo is better at several things:

Where Slova wins

Slova is better for learners who've outgrown the basics:

The verdict

Duolingo and Slova aren't really competitors - they're complements. Duolingo is the on-ramp: it teaches you to read Cyrillic, recognize basic patterns, and build a daily habit. Slova is the training gym: it's where you do the hard reps that turn passive recognition into active knowledge.

If you're just starting Russian, start with Duolingo. When you hit the wall - when you realize you can recognize words but can't decline them, when multiple choice feels too easy but free writing feels impossible - that's when Slova becomes essential.