AnkiSpaced repetition · since 2006

Flashcards, scheduled by algorithm

Review a card the day before you would have forgotten it

Anki tracks how well you knew each card and pushes the next review to the last useful moment. That is the entire product — and it is why medical students and language learners keep decks alive for a decade.

Front

saudade

a longing for something absent, with affection for having had it

Again<1 min Hard6 min Good3 days Easy8 days

Illustrative card. The four buttons are the only input the scheduler needs.

The idea

Rereading feels productive and mostly is not

Memory decays on a curve. Read something once and most of it is gone within days. The intuitive fix — read it again, and again — is inefficient, because each rereading happens while you still remember, which teaches your brain very little.

Retrieval right at the edge of forgetting is what actually consolidates. That timing is impossible to manage by hand across a thousand cards, which is precisely the job Anki takes over: it records how each card went and schedules the next appearance accordingly.

Retention over timeillustrative
without review with spaced review
10mfirst miss
1dnext day
3dif easy
8dsettling in
21dsolid
2mo+long term

Intervals stretch as long as you keep answering correctly, and collapse the moment you do not. The numbers above are indicative — the real schedule adapts per card.

Platforms

Free on Android, paid on iPhone — and that is deliberate

This trips people up, so it is worth stating plainly. The Android app is community-built and free. The iOS app is written by Anki's lead developer and sold at a computer-software price; those sales fund the desktop version, the sync service and the ecosystem everyone else uses for free.

AnkiDroid — Android

Free

Open source, maintained by volunteers. Full compatibility with desktop Anki and AnkiWeb sync. Also available on F-Droid.

Google Play

AnkiMobile — iPhone & iPad

Paid, one-off

Written by the developer of Anki itself. One purchase, no subscription. The price funds development of the whole project.

App Store

Check the developer before you install

Anki's popularity attracted a wave of copycats using the name on both stores, several of them charging expensive subscriptions and none of them compatible with the real ecosystem. The official iOS app is AnkiMobile Flashcards by Anki Software / Ankitects; the official Android app is AnkiDroid Flashcards by the AnkiDroid Open Source Team. Anything else with "Anki" in the title is not part of the project.

Reality check

It is powerful and it is not friendly

Worth the learning curve if

  • You have a large volume to memorise over months — vocabulary, anatomy, law, exams
  • You want your data in a file you own, syncing free across devices
  • You will actually review most days; skipping a week creates a painful backlog
  • You are willing to write good cards, which is a skill in itself

Look elsewhere if

  • You want a polished, guided app — the interface is dense and dated
  • You need to memorise something once, for next week
  • Configuring deck options sounds worse than the studying
  • You would rather buy premade content than build it

Do I need to make my own cards?

No — thousands of shared decks exist for languages, medicine and more. But cards you write yourself almost always work better, because writing them is already studying.

Does syncing cost anything?

AnkiWeb sync is free, and works between phone, desktop and the browser.

What happens if I skip a week?

Reviews accumulate and the next session is brutal. The fix is small daily sessions rather than heroic weekend catch-ups.

Does it work offline?

Yes. Cards and media live on the device; sync is only needed to move progress between devices.

Get it

Start with twenty cards, not two hundred

The most common failure is loading a 3,000-card deck on day one and drowning by day nine. Twenty new cards a day is a pace you can hold for a year.

AnkiDroid — free AnkiMobile — iOS