Onboarding language learners to increase retention.

Introduction

Babbel is a paid, subscription-based language learning app for web and mobile. Unlike many competitors, Babbel targets users who are serious about learning, and offers a more traditional experience like a textbook.

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The challenge

To support the company's retention goals, the product team decided to run a quick A/B test to evaluate whether users would engage with learning streaks. This involved adding a tapable streak icon with an onboarding tooltip to the mobile app.

The tooltip message needed to be short and localisable into 8 languages, which significantly limited the available space.

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A streak activates when users complete a learning activity, and stays active as long as they complete an activity every day.

My approach

I was brought in early, to define what we need to tell users to keep them engaged. It was important to accommodate for users who were familiar with streaks from other apps, but also for users who weren't. So, I planned to do a comprehension test before going live.

Looking into habit builders

Popular education apps like Duolingo share consistent patterns:

• ✓An upbeat, encouraging tone.
• ✓Clear guidance on how to maintain a streak and the risk of losing it.
• ✓Treating the start of a streak as a milestone.

These apps typically use full‑screen onboarding rather than tooltips, so I had to carefully balance how much information to include.

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Creating the first drafts

To onboard users, the tone had to be encouraging and instructional.

I initially only focused on what the user should do to maintain their streak, to keep the tooltip short.

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Clarifying what counts

A discussion with the product manager, designer, and engineering team, revealed that streaks only increase with specific learning activities. This meant the tooltip needed to be more precise.

I revised the copy to mention the relevant activities, and to highlight that the user is already on a streak, I framed it as a milestone.

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Ensuring users understand streaks

To quickly test the tooltip with potential users, I ran a small, unmoderated comprehension test on Lyssna. I sent a design survey to Babbel's largest market, and collected qualitative feedback through 4 short questions.

Around 90% of the participants understood how streaks worked, so we moved forward confidently.

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Supporting with localisation nuancies

The tooltip was localised into 8 languages. To keep the message concise, I asked the localisation team to stay within 3 lines of text.

Following Babbel's localisation guidelines, I agreed to use "Learning tempo" with the German linguist as the German term for streaks.

For Swedish, it was surprising to find out that no equivalent term existed among competitors. The Swedish linguist and I agreed not to reference streaks directly, and instead encouraged users to "keep it up".

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Impact

The A/B test had overall positive results, and streaks were rolled out to all Babbel users. Users with streaks learned for more consecutive days. Streaks went on to become a core engagement‑driving feature.

Feedback

“Hary has been pivotal for the success of the streaks features that we developed this year. His project management when coordinating complex translations, handling keys, and multiple projects simultaneously was impressive and made me as a designer always feel that he had it under control.”

Next steps

The limited space in the tooltip was addressed in later iterations as more streak‑related screens were designed and implemented.

Even though this began as a small A/B test, streaks ultimately became a foundational part of Babbel's engagement strategy.