Best Vocabulary Apps: Anki vs Quizlet vs Duolingo vs Tomaru

The best vocabulary app is the one that still has you remembering the words months later, which means it needs ready-to-use decks, spaced repetition that brings each word back before you forget it, and a way to use the words. Duolingo is best for a daily language habit, Quizlet for turning your own lists into flashcards, Anki for a fully customizable spaced repetition system, WORD UP and WordCow for exam word banks, and Tomaru for ready-made decks with automatic FSRS scheduling.

The most common failure in vocabulary learning is not that people never study. It is that they study for a few days and then forget. Without spaced repetition, review scheduling, active recall, and practice that uses the words, daily streaks can still mean you only saw many words without truly remembering them. A useful vocabulary app should be judged by one standard: can it help you still remember these words six months later?

Why “learning many words” is not the same as effective learning

The real issue is not how many words you see, but how many words you can recall.

Many apps create a strong feeling of progress: completing levels, keeping streaks, finishing lessons, or increasing a known-word count. These numbers can motivate users in the short term, but they measure exposure, not long-term memory.

Common misleading signals include:

Seeing a word is not remembering it. You can quickly swipe through a word list and feel familiar with everything, but fail to recall the meaning with your eyes closed. Recognition and recall are different, and recall strengthens memory much more.

A streak is not memory. Completing daily tasks for 30 days does not mean all words from those 30 days remain in memory. Without review at the right time, many words start fading within days.

Finishing a course is not remembering. If you finish all words in one topic and move to the next, you may forget much of the earlier topic by the time you need it.

A large word list is not memory. A deck with 2,000 words does not mean you know 2,000 words. A word is truly learned only when you can recall it when needed.

Long-term recall is the standard for effective vocabulary learning.

What should a vocabulary app be judged by?

Before looking for vocabulary app recommendations, ask three questions.

1. Does it have useful vocabulary decks?

A deck is not just a list of words. The important question is whether it is organized, matches your learning goal, and lets you start without preparing all material yourself.

A good deck should be organized by purpose. Exam preparation, daily situations, and workplace vocabulary need different word selection. If an app does not organize decks by use case, or requires you to type and organize everything yourself, it solves only part of the problem.

2. Does it have spaced repetition or spaced review?

Vocabulary learning without a review schedule is mostly short-term memory practice. If a word does not return at the right time after you learn it, memory naturally fades.

Spaced repetition schedules each card's next review based on your memory performance. Difficult words return sooner; familiar words get longer intervals. This concentrates review on what actually needs reinforcement instead of rereading the same list every day. Without this mechanism, an app may help you see more words, but not remember them.

3. Does it help you use the words?

Knowing a word's meaning is the first step, not the end. A word becomes active vocabulary only when you can use it in the right context. Example sentences help with context, grammar practice gives words structure, and translation or speaking practice makes usage more natural.

If an app only has a “memorize and review” loop but no way to use words, many words remain passive and fail to appear when you need them.

Why spaced repetition is the core of a vocabulary app

Spaced repetition matters because it directly solves the core memory problem: forgetting.

The forgetting curve shows that after learning something, memory does not stay stable. It declines over time. Without review, much of it can disappear within days. If you review before forgetting, memory strength rises again and the next decline becomes slower. After several cycles, a word can stay in memory longer without being relearned every day.

Spaced review automates this process. Users do not need to decide which words to review today. The system uses each card's familiarity to decide when it should appear again. Active recall, meaning trying to remember before checking the answer, is what makes the process work.

FSRS, or Free Spaced Repetition Scheduler, is one of the more modern scheduling algorithms. Instead of using fixed rules for every interval, it uses your recall result on each card to estimate memory state and forgetting risk, then schedules a better review time. This is especially useful for vocabulary learning because word count is large, familiarity varies by word, and memory must be maintained over time.

Without spaced repetition, even a feature-rich or entertaining app struggles to solve the real problem: words learned today disappear later.

Common types of vocabulary apps

Prices and sources

What each app charges, taken from the official App Store listings and help pages on October 4, 2026. App Store prices are US prices and vary by country.

Is Duolingo good for vocabulary learning?

Duolingo is good for building a language habit, but it is not designed around large vocabulary decks and card-level spaced scheduling.

Its strength is gamification and daily tasks. It helps beginners get started and build a habit of touching the language every day. For people who want a small daily language routine, it can be useful.

But if the goal is systematic vocabulary growth, such as exam preparation, topic-specific vocabulary, or long-term tracking for each word, Duolingo is not the most specialized tool. Its learning path is fixed, word management is limited, and review is not primarily based on each word's memory performance.

Is Quizlet good for vocabulary learning?

Quizlet is useful when you already have material and want to turn it into flashcards.

Its interface is intuitive, and it supports card flipping, matching, fill-in practice, and many community study sets. If you have a teacher's word list or textbook vocabulary, Quizlet is a convenient way to turn that material into cards.

Its limits are clear: community set quality depends on the creator, and users without existing material may still need to organize decks themselves. Quizlet's App Store listing describes a spaced repetition feature that resurfaces what you need to review. It is good for people who already have content, but not always the easiest option for people who want ready-made decks.

Is Anki good for vocabulary learning?

Anki is one of the most complete spaced repetition tools and has a long history among language learners and medical students.

Its strength is deep customization. Card format, deck structure, review parameters, and FSRS settings can all be adjusted. For people willing to configure it, Anki can become a powerful learning system. There are also many shared decks, and the desktop app, AnkiWeb and AnkiDroid are free.

But Anki can be difficult for people who just want to start learning words. Beginners need to understand decks, note types, templates, and fields. Finding reliable decks takes time, and configuring FSRS adds another learning layer. We go deeper in Is Anki good for vocabulary?

Anki is not bad. It assumes users are willing to study the tool itself. For people who want to start vocabulary learning today, that assumption may not fit.

Is WORD UP or WordCow good for vocabulary learning?

Both are built around exam word banks for Chinese-speaking learners of English. WORD UP covers exams such as TOEIC and Taiwan's college entrance exam, and lets you make and review your own cards for free. WordCow covers TOEIC, TOEFL, GEPT and Taiwan's college entrance exam vocabulary with pronunciation, example sentences, three quiz types and review lists.

They fit learners with a specific English exam date. For learners outside those exams, or learning a language other than English, the word banks are narrower.

Who is Tomaru for?

Tomaru is for people who want to start vocabulary learning directly without studying the tool first, and who need a system they can keep using long term.

It provides official vocabulary decks covering exam preparation, daily situations, and common vocabulary, such as JLPT N5 Japanese, TOPIK I Korean and HSK 1–2 Chinese. Users do not need to search for decks or judge their quality before starting. FSRS spaced repetition automatically schedules review, deciding when each card should appear again based on memory performance. Tomaru's core vocabulary features are free forever, with no ads.

Its AI card creation feature can turn articles, lyrics, conversations, or news into vocabulary cards, so language material from daily life can become reviewable. Words you have learned can also connect to grammar practice, shadowing, and bidirectional translation, helping vocabulary move from “I know the meaning” to “I can use it.”

Tomaru does not try to replace Anki's extreme customization or Duolingo's gamified habit building. It solves a more specific problem: spaced repetition, ready-made official decks, and no tool setup before starting.

How to judge whether a vocabulary app is effective

Before choosing a vocabulary app, use these questions to judge whether it can actually help you remember words long term:

• Does it bring old words back? If the app only moves forward linearly, previously learned words fade quickly.
• Does it adjust review based on memory state? One fixed cycle for every word is very different from card-level scheduling.
• Does it require recall before showing the answer? Active recall strengthens memory much more than immediately seeing the answer.
• Does it provide organized decks? If you must type many words yourself, many learners quit before starting.
• Can the core workflow stay free long term? If key functions are paid, the free learning flow may be incomplete.
• Does it make you remember, or only make you keep a streak? Streak satisfaction and real memory are different.
• Does it help you use the words? Without a usage path, vocabulary often stays passive.

Final recommendation

Choose based on your goal:

• Build a daily language habit as a beginner: Duolingo
• Turn existing material or word lists into cards: Quizlet
• Fully customize a spaced repetition system: Anki
• Prepare for a specific English exam: WORD UP, WordCow, or other exam-focused apps
• Use ready-made official decks + FSRS spaced repetition + ad-free learning to remember words long term: Tomaru

These tools do not have to be mutually exclusive. Some learners use Duolingo for daily habit building and Tomaru or Anki for systematic vocabulary memory. The key is finding a setup you can keep using and that actually helps you remember words long term.

FAQ

What is the best vocabulary app?

It depends on the goal. Duolingo suits a daily language habit, Quizlet suits turning your own word lists into flashcards, Anki suits learners who want to customize a spaced repetition system, WORD UP and WordCow suit specific English exams, and Tomaru suits learners who want ready-made decks with automatic FSRS scheduling and no setup.

What should I look for in a vocabulary app recommendation?

Look for three things first: organized vocabulary decks, spaced repetition or spaced review for long-term memory, and a free core workflow that lets you learn and review without interruption. Interface design and gamification matter less if the app cannot help you remember words later.

Are more features always better in a vocabulary app?

No. More features can mean more options, but also more complexity. If the core deck, spaced review, and practice flow are weak, extra features cannot solve forgetting. Choose based on whether the core learning loop works, not whether the feature list is longest.

Why do I still forget words after using vocabulary apps?

The two most common reasons are lack of spaced repetition and lack of active recall. If learned words do not return at the right time, they fade. If you only look at answers instead of recalling first, memory is weaker. Use a tool with scheduled review and build the habit of recalling before checking.

Does a vocabulary app need spaced repetition?

If your goal is long-term memory, yes. Apps without spaced repetition may expose you to more words, but they struggle to move those words into long-term memory. The forgetting curve shows memory declines over time. Spaced repetition automates review before forgetting.

Is Duolingo good for vocabulary learning?

Duolingo is good for building a language habit and beginner exposure, but it is not specialized for large vocabulary decks or card-level scheduling. For exam preparation or systematic vocabulary growth, it usually works better alongside a tool focused on spaced review and word tracking.

Is Quizlet free?

Quizlet is free to download and you can make and study basic flashcards for free. Quizlet Plus is listed at $9.99 and $44.99 on the US App Store (checked October 2026).

Is Anki good for beginners?

Anki is powerful, but beginners may face setup friction. They need to understand decks, note types, templates, and fields, then find or build reliable decks. The official iOS app costs $24.99 in the US (checked October 2026). Anki is best for people willing to study the tool for maximum flexibility.

Is there a free, ad-free vocabulary app with spaced repetition?

Yes. Tomaru's core vocabulary features are free forever, with no ads. It offers official vocabulary decks and FSRS spaced repetition scheduling, making it suitable for people who want to start without tool setup.

What is the difference between Tomaru and Anki?

Both use spaced repetition, but they have different design directions. Anki gives users maximum control and customization, but has higher setup cost. Tomaru provides official decks and automatic FSRS scheduling with lower friction, for people who want to start learning vocabulary directly.

Is Tomaru suitable for long-term vocabulary learning?

Yes. Tomaru uses FSRS spaced repetition to bring words back before you forget them, offers ready-made official decks, and its core vocabulary features are free forever, with no ads. Learned words can also connect to grammar practice, shadowing, and bidirectional translation, so vocabulary can move from memory to use.