You learn twenty new words on Sunday. By Friday most of them feel fuzzy. That is not a character flaw. It is how memory works when you do not review on time.
If you want the longer story of that drop-off, start with Why You Forget 80% of New Words. This piece is narrower: what FSRS means when your goal is vocabulary, not a settings hobby.
Spaced repetition in one paragraph
Spaced repetition means you see a word again right before you would forget it. Early on, that might be tomorrow. After a few good recalls, it might be next week, then next month. Think of watering a plant: too often wastes time, too rarely and it dies. The schedule stretches as the memory gets stronger.
A fixed calendar (“every three days, forever”) is better than cramming, but it does not know which words are easy for you and which keep slipping.
What FSRS adds (plain words)
FSRS stands for Free Spaced Repetition Scheduler. In practice it means:
- After each review, you rate how hard the card felt.
- The scheduler updates its guess of how stable that memory is.
- The next due date moves earlier or later based on your history, not a one-size calendar.
You do not need to understand the math. You need honest ratings. If you mash “easy” on cards you barely know, any scheduler will lie to you.
What this is not: a promise that you will study less forever, or a claim that one algorithm number is magic. It is a better default for “show me this word when I am about to lose it.”
How this shows up in a simple review loop
The loop is simple:
- You create a card (word, translation, image you chose).
- When it is due, you try to recall it.
- You rate the recall.
- FSRS sets the next interval.
You are not tuning parameters. You are practicing vocabulary on a schedule that adapts to your memory. Pictures help many people encode the word in the first place; the scheduler helps you meet it again in time. Neither one is a full language course.
Honest limits
FSRS will not:
- Teach you a whole grammar path or conversation skills by itself
- Fix a deck of junk cards (vague prompts, no context, ratings you do not mean)
- Guarantee fluency
It will help a focused vocab habit: fewer “I swear I knew this last week” moments, if you show up and rate honestly.
When you need the grammar behind a word, use a free guide and then burn the vocab in with reviews. For example, German gender pairs well with German articles: der, die, das, and Spanish “to be” pairs with ser vs estar. More guides live in the grammar hub.
A small practice you can start today
Pick five words you keep forgetting. Make each one a card you can actually picture. Review when due. Rate honestly. That is the whole loop.
If you want that loop in the product, open How Vidi Works when you are ready and create one card.