Harken
Harken uses spaced repetition to optimize your studying.
At a glance
Starts at
$4 per month
Price as published by the vendor, September 2026.
Free tier
No
Platforms
Web
Best for
Students, professionals, learners
Not for
Learners without internet access
3.8 out of 5
Scored by a Toolio reviewer after real useOur verdict
Harken excels in spaced repetition but is limited by its reliance on this single method. It’s not suitable for those needing a variety of study techniques.
✓What it does well
Spaced RepetitionHarken schedules reviews to optimize long-term memory retention.
Flexible FormatSupports rich text, images, inline code, and code blocks.
Easy AccessAvailable on any device via a responsive web app.
✕Where it falls short
Lacks VarietyDoes not offer diverse study methods beyond spaced repetition.
No Offline SupportCannot be used without an internet connection for reviews.
Limited Import OptionsOnly supports importing Anki decks, not other formats.
Key features
Web ExtensionChromecast extension to quiz yourself on web content.
Stats TrackingTracks and displays your learning progress visually.
Import Anki DecksImports all decks and review history from Anki.
Offline Review SupportAllows reviewing cards without an internet connection.