Flash Vocabulary Builder
Learn and retain English vocabulary with spaced repetition flashcards, multiple-choice quizzes, and type-it spelling drills. 320 words across Beginner, Intermediate, Advanced, and Professional levels. Add your own words. Progress saved in your browser — no signup needed.
Leitner boxes
Box 1 = new · Box 5 = mastered
Deck
Study mode
How the Vocabulary Builder Works
- 1Choose a deck and level. The built-in deck has 320 words across Beginner, Intermediate, Advanced, and Professional tabs. Switch to "My words" to study a custom list, then pick Classic, Multiple Choice, or Type-It.
- 2Work through the session. Each session shows up to 20 cards — due cards first, sorted by Leitner box so the most-forgotten words appear earliest.
- 3Rate your recall honestly. In Classic mode, Again/Hard moves the card backward; Good/Easy advances it. The next review date is set automatically by the box interval.
- 4Return each day. Study the due cards shown on the dashboard. Consistent short sessions beat long infrequent ones — 10 minutes a day compounds fast.
Why Spaced Repetition Works
The forgetting curve, first described by Hermann Ebbinghaus in 1885, shows that memory decays exponentially without reinforcement. Spaced repetition exploits this by scheduling a review just before forgetting occurs. Each successful recall stretches the interval — so a word reviewed today, then tomorrow, then in 3 days, then in a week, then in two weeks becomes deeply embedded in long-term memory with only five total sessions.
Tips for Faster Vocabulary Retention
Study in the morning
Sleep consolidates memory. Studying before sleep and reviewing in the morning captures both windows of consolidation.
Say the word aloud
Use the speaker button in Classic mode. Phonological encoding (hearing a word) reinforces orthographic encoding (reading it).
Create your own mnemonics
The built-in memory hooks are starting points. Your own associations — absurd, personal, vivid — stick far better.
Use Type-It for hard words
If a word keeps escaping you in Classic mode, switch to Type-It for a session. Spelling forces deeper retrieval effort.
Add words from your reading
When you encounter an unfamiliar word in an article or book, add it immediately with its original example sentence. Context anchors meaning.
Rate honestly, not optimistically
Marking a word Easy when you hesitated only delays the forgetting. Rate Hard if it took more than a second — the extra reviews pay off.
Frequently Asked Questions
What is spaced repetition and how does it work here?
Spaced repetition is a learning technique that schedules review sessions at increasing intervals based on how well you know each word. Words you find difficult are shown more often; words you know well are shown less frequently. This tool uses a Leitner box system with 5 boxes. New words start in Box 1 and advance toward Box 5 (mastered) as you rate them correctly. The intervals are: Box 1 = same session, Box 2 = 1 day, Box 3 = 3 days, Box 4 = 7 days, Box 5 = 14 days.
What is the difference between the three study modes?
Classic Flashcard shows the word on the front and definition on the back. You flip the card and rate your recall (Again, Hard, Good, Easy). Multiple Choice shows the definition and asks you to pick the correct word from four options — good for building recognition. Type-It shows the definition and asks you to spell the word from memory — the most challenging mode and the best for deep encoding.
How is my progress saved?
Progress is saved automatically in your browser's localStorage. This means your box assignments, review schedules, and streaks persist between sessions as long as you use the same browser and do not clear site data. No account or server is involved.
Can I add my own words?
Yes. Switch to "My words" in the Deck selector and click "+ Add word". You can enter the word, part of speech, definition, an example sentence, and an optional memory hook (mnemonic). Your custom words are stored in localStorage alongside your progress.
What are the built-in words?
The built-in deck has 320 words across four levels: 80 Beginner (everyday academic vocabulary), 80 Intermediate (B2-C1 level), 80 Advanced (SAT/GRE and C1-C2), and 80 Professional (business, legal, and financial terms). You can study all 320 at once or filter to a single level.
What does the Leitner box chart show?
The five bars represent the five Leitner boxes. Box 1 (red) contains new or difficult words reviewed frequently. Box 5 (purple) contains mastered words reviewed infrequently. As your study sessions advance words through the boxes, the bars shift — you want to see the chart weighted toward boxes 4 and 5.
What does the pronunciation button do?
In Classic Flashcard mode, a speaker button appears on the front of each card. Clicking it uses the browser's built-in Web Speech API to speak the word aloud in English. Hearing the word alongside reading it reinforces phonological memory, which speeds up long-term retention.