The biggest frustration in learning Chinese: you study a character, recognize it for a few days, then forget it completely. Spaced repetition solves this.
In 1885, psychologist Hermann Ebbinghaus discovered that memory decays exponentially after learning. Without review, you forget roughly 50% of new material within a day and 80% within a week. But each review at the right moment resets and extends the curve. After 4–5 well-timed reviews, information moves into long-term memory where it stays for months or years.
The idea is simple: review a character right before you would forget it. If you get it right, the next review is scheduled further out. If you struggle, the interval shrinks. A typical progression looks like this:
Each successful review roughly doubles the interval. A character you've reviewed 6 times might not appear again for 6 months — and you'll still remember it.
Chinese has thousands of characters that differ by small details. Without systematic review, similar characters (己 vs 已 vs 巳) blur together. Spaced repetition keeps each character distinct in your memory by testing recognition at precisely calibrated intervals.
Anki is an excellent general-purpose tool, but it requires significant setup: creating decks, formatting cards, configuring intervals. Hanlexon's review system is purpose-built for Chinese: