Duolingo and Babbel are usually the first two names anyone hears when they start looking for a language app, and they solve different problems. Duolingo is free to use indefinitely, supported by ads and built around short, game-like exercises; Babbel is a paid, structured course, with the first lesson of every language free to try before a subscription is required. Neither app has an Apple Watch app, and neither puts vocabulary on your Lock Screen. The comparison below is based on what each company states on its own site, help centre and App Store listing, checked in September 2026.
| Duolingo | Babbel | |
|---|---|---|
| Price model | Free to use indefinitely, supported by ads and an energy system in the app that runs down as you practise (hearts on the web); Super Duolingo removes the ads and that limit, and Duolingo Max, mobile-app only, adds AI features on top. | No free way through the courses: registration and the first lesson of every course are free to try, then a subscription is required for the rest, priced by location, duration and platform. |
| Platforms | iPhone, iPad and Apple Vision Pro, plus Android and the web; no Apple Watch app. | Web browser, iPhone/iPad (iOS 17 or later) and Android (9.0 or later); no Apple Watch app. |
| Lesson style | Short, game-like exercises — speaking, reading, listening and writing, from translation to multiple choice — with streaks and leaderboards. | A structured curriculum built around a goal you choose at sign-up, with gradual progression and review built into each lesson. |
| Speaking practice | Speaking exercises inside ordinary lessons; its paid tiers add AI Roleplay and Video Call practice in the mobile app, for a limited set of courses. | Guided Conversations with speech recognition, plus an AI partner called Babbel Speak; on the web, recognition works best in Chrome and, in Edge, Firefox or Safari, only for German, Italian, Spanish and French. |
| Grammar explanations | Explain My Answer gives a short, personalised explanation after an answer, right or wrong, free since January 2026 in its Spanish, French, German, Japanese, Portuguese, Italian and Korean courses. | Grammar taught in context, worked into the lesson before you are tested on the point. |
| Who it suits | Someone who wants a free, low-commitment daily habit and does not mind ads or an energy limit on free practice. | Someone ready to subscribe after one free lesson, in one of Babbel's 13 languages for English speakers, in exchange for a fixed course. |
How the lessons differ
Duolingo's lesson is a short, game-like loop: a handful of exercises — translating a sentence, answering a multiple-choice question, listening, or speaking a phrase into the microphone — strung together into a few minutes, with streaks, a leaderboard and playful rewards keeping you coming back, as Duolingo's own App Store listing describes it. The free version works this way indefinitely; paying for Super Duolingo removes the ads and the energy limit, without changing the lesson format itself.
Babbel's lesson sits inside a fixed course instead. You choose a goal when you sign up — travel, work, or fun — and Babbel builds a path toward it, with what its own method page describes as gradual progression and review built into and at the end of each lesson. Some extras, such as its podcasts, are free, but there is no free way through the course: the first lesson of every course is free to try, and the rest requires a subscription.
Grammar and speaking, treated differently
The two apps differ in when a grammar rule actually gets explained. Duolingo's Explain My Answer works after the fact: tap it after an answer, right or wrong, and the app offers a short, tailored note about the rule involved, free since January 2026 in its Spanish, French, German, Japanese, Portuguese, Italian and Korean courses. Babbel's grammar explanations sit the other way round, worked into the lesson itself before you are tested on the point, which its App Store page describes as "grammar in context".
Speaking practice is uneven on both sides, too. Duolingo's free and Super tiers include speaking exercises inside ordinary lessons, but the more open-ended practice — AI Roleplay and Video Call practice — belongs to Duolingo's paid tiers in the mobile app rather than on the web, and only covers a handful of course pairs so far. Babbel's Guided Conversations use speech recognition that, per Babbel's own system requirements page, works best in Chrome on the web and, in Edge, Firefox or Safari, only recognises German, Italian, Spanish and French.
Which one to pick
Pick Duolingo if…
- You want to start today without paying anything, and do not mind ads or a daily limit on how much you can practise for free.
- A game-like habit — streaks, short daily sessions, a leaderboard — is what actually gets you to open the app.
- You are comfortable picking up grammar from a note after you answer rather than an explanation up front.
Pick Babbel if…
- You would rather follow a fixed course toward a stated goal than choose your own path through a skill tree.
- You want a grammar point explained before you are tested on it, not after you get it wrong.
- You are ready to subscribe once the first free lesson ends, in one of Babbel's 13 languages for English speakers.
Where passive vocabulary fits alongside either
Both apps review vocabulary, and Babbel's method page describes spaced repetition, but that review happens inside a session you have to open. Between sessions, the words have no way to reach you. Duolingo and Babbel both teach grammar and both include some form of speaking practice — real instruction, which is worth reading more about in the best ways to learn a language. Watch Your Language does not attempt either job. It is a passive-vocabulary tool: no lessons, no grammar explanations, no speaking or listening practice of its own.
For a sense of how much vocabulary a working level actually needs, see how long it takes to learn a language; for how the scheduling itself works, see spaced repetition, explained.
Watch Your Language does not compete with Duolingo's lessons or Babbel's course — it has no lessons of its own to compete with. What it does is keep the vocabulary from either app in view once the session ends: words appear a few at a time on your iPhone Lock Screen and Home Screen, on iPad, and as Apple Watch complications on the watch face, brought back more often when you have been forgetting them. Typed-in words, a CSV or spreadsheet import, or a photograph of your own notes all feed the same schedule, so a course's vocabulary list can end up on your wrist too.
