Spaced repetition for vocabulary: a practical guide for 2026

You can look a word up ten times and still not know it. The reason isn't your memory — it's your timing. Reviewing a word right after you saw it teaches you almost nothing. Reviewing it just as you're about to forget it teaches you a lot. That timing trick has a name: spaced repetition.

The forgetting curve

Over a century ago, Hermann Ebbinghaus showed that memory decays predictably. Learn something new and you'll forget most of it within days — unless you revisit it. Each time you successfully recall something, the memory gets more durable and the next review can wait longer.

Spaced repetition exploits this. Instead of cramming, you review each item at expanding intervals: a day later, then a few days, then a week, then a month. Every review you pass pushes the next one further out. Items you struggle with come back sooner.

The result is brutally efficient: you spend your review time only on the things you're actually about to forget.

Why it works so well for vocabulary

Vocabulary is the perfect use case. A language has thousands of words, each independent, each needing to survive long-term. You can't cram 5,000 words — but you can maintain them with a few minutes of well-timed review a day.

Done right, spaced repetition lets you:

• Remember more with less time. No re-reviewing words you already know cold.
• Trust the system. You don't decide what to study today; the algorithm does.
• Scale. The same daily habit works whether you know 200 words or 12,000.

The mistakes that ruin it

Most people who "tried flashcards and it didn't work" hit one of these:

1. Reviewing out of context. A word stripped of any sentence is hard to anchor. Learn words in the sentences you met them in.
2. Making cards a chore. If building cards takes longer than reviewing them, you'll quit. Saving should be one tap.
3. Burying yourself. Adding 100 new words a day creates a review avalanche. Add steadily; let the queue stay manageable.
4. Ignoring the schedule. Skipping days defeats the timing. A short daily session beats a giant weekly one.

FSRS: the modern algorithm

Early systems used fixed interval rules (the classic SM-2 from the 1980s). Modern tools use FSRS (the Free Spaced Repetition Scheduler), which models each item's memory with far more nuance — estimating how stable a memory is and how likely you are to recall it on any given day, then scheduling the review for the moment it'll do the most good.

In practice that means fewer reviews for the same retention. The algorithm adapts to your memory instead of forcing your memory to fit a fixed schedule.

Making it effortless

The best spaced-repetition habit is the one you don't have to maintain by hand. Here's the low-friction version:

• Meet words in real reading, not in a deck-building session.
• Save the ones worth keeping in a single click, with their sentence attached.
• Let the scheduler decide when they come back.
• Review for a few minutes a day, wherever you are.

That's exactly the loop bleam builds in. As you read the web at your level, you save words in context, and bleam schedules them with FSRS so they resurface right before you'd forget — no decks to build, no intervals to manage.

Want your vocabulary to actually stick this time? Start with bleam — free for 14 days, no card required.