Anki is the free, open-source spaced-repetition flashcard app trusted by millions of students. See how it works, pricing across platforms, and key features.
Anki is a free, open-source flashcard application that uses spaced repetition to help users memorize information more efficiently than traditional study methods. It was created in 2006 by Australian developer Damien Elmes, who built the first version to help himself learn Japanese.
Rather than a single app, Anki is an ecosystem of clients that all sync through AnkiWeb: a free desktop app for Windows, macOS, and Linux; a free, community-built Android app called AnkiDroid; a free web client at AnkiWeb; and a paid iOS app called AnkiMobile that funds the rest of the project.
Anki's name comes from the Japanese word for memorization (an-ki). It has become especially popular in medical education, language learning, and any field that requires memorizing large volumes of discrete facts.
At its core, Anki uses an algorithm that schedules each flashcard for review at increasing intervals based on how easily the user recalls it, showing difficult cards more frequently and easy cards less often.
Users can create custom card templates, including cloze deletions (fill-in-the-blank cards), image occlusion, and cards with audio or images, making it suitable for subjects ranging from anatomy to vocabulary.
A large add-on ecosystem lets users extend Anki with statistics dashboards, custom review heatmaps, and integrations with other study tools, and a large community of users shares pre-built decks for common subjects like medical boards, language vocabulary, and standardized tests.
Anki is free on desktop (Windows, macOS, Linux) and on Android via AnkiDroid, and free to use on the web through AnkiWeb, which also provides free cloud sync across all devices.
The only paid component is AnkiMobile for iOS, a one-time purchase of around $24.99 in the US with no subscription and no recurring fees; Apple sets regional pricing tiers for other currencies.
The iOS purchase price is explicitly used to fund ongoing development of the entire free ecosystem, since the desktop, Android, and sync components do not generate direct revenue on their own.
Yes, Anki is free on Windows, macOS, Linux, and Android, and the AnkiWeb sync service is also free. Only the iOS app, AnkiMobile, requires a one-time purchase.
The AnkiMobile purchase price funds ongoing development of the entire free Anki ecosystem, since the desktop, Android, and web clients do not generate direct revenue.
Anki was created in 2006 by Australian developer Damien Elmes, originally to help him learn Japanese vocabulary.
Yes, AnkiWeb provides free two-way sync so decks and review progress stay consistent across desktop, mobile, and web.
Yes, Anki is widely used by medical students, with pre-built shared decks covering common board exam content, and is frequently cited as one of the most popular study tools in medical education.
AnkiHub is a company founded by Nick Flint and Andrew Sanchez that grew out of the Anki community; as of early 2026 it is gradually taking over stewardship of Anki's open-source development from creator Damien Elmes.
Yes, the desktop and mobile apps work fully offline and sync progress automatically once you reconnect to the internet.