Spaced Repetition is a learning technique based on the spacing effect — the psychological principle that information is better retained when reviewed at gradually increasing intervals. Instead of cramming, you review flashcards just before you're about to forget them. This tool uses an SM-2 algorithm (similar to Anki) that adjusts review intervals based on your performance: cards rated "Easy" get longer intervals, while cards rated "Again" reset to short intervals. Research shows this method can improve long-term retention by 200-300% compared to massed practice.

Effective flashcards follow the minimum information principle: each card should contain one atomic fact or concept. Keep questions concise and specific. Use active recall — phrase questions to trigger retrieval, not recognition. For language learning, put the target word on one side and definition/translation on the other. For concepts, use cloze deletions or question-answer format. Avoid long paragraphs; break complex topics into multiple cards. Images and mnemonics on the answer side can further boost retention.

These ratings tell the algorithm how well you recalled the answer: Again — you couldn't recall it; the card resets to a 1-minute interval. Hard — you recalled with significant difficulty; interval increases slightly (1.2×). Good — you recalled correctly with normal effort; interval grows by the ease factor (default 2.5×). Easy — effortless recall; interval grows even more (3.25×) and the ease factor increases. Be honest with your ratings — this ensures the algorithm accurately predicts when you'll next need to review.

For optimal results, study daily and review all due cards each day. The spaced repetition algorithm schedules reviews at strategic intervals, so daily engagement ensures you never miss a review window. A typical session takes 10-20 minutes depending on your deck size. Consistency matters more than session length — even 5 minutes daily yields better long-term retention than weekly marathon sessions. Morning reviews are often most effective when your mind is fresh.

Yes! All your flashcards and learning progress are automatically saved in your browser's local storage — no account needed. Your data persists across sessions on the same device and browser. You can export your entire deck as a JSON file for backup or sharing. Use the Import button to restore cards or merge decks. Note that clearing browser data will delete your flashcards, so we recommend exporting regularly as a backup.

The SM-2 algorithm (SuperMemo 2) was developed by Piotr Woźniak in 1987 and remains one of the most influential spaced repetition algorithms. It tracks three variables per card: repetitions (how many times you've successfully recalled it), ease factor (starting at 2.5, adjusts based on your ratings), and interval (time until next review). Each rating modifies these values: "Good" multiplies the interval by the ease factor, "Easy" adds a bonus multiplier, "Hard" reduces the ease factor, and "Again" resets repetitions. This adaptive system personalizes the learning schedule to your memory patterns.