Announcing Harken, a New Spaced Repetition Flashcard App

Today we're publicly announcing Harken, a smart flashcard app that uses spaced repetition to make remembering easy. We started Harken because everyone has trouble remembering what they learn. Most people who read books or take online classes either accept that they'll forget, or they spend even more time and money relearning what they forgot. That applies to us, too—as lifelong learners, we've experienced this firsthand, and it's super frustrating. With Harken, we're making this a problem of the past—try the app for yourself here.

What is Harken?

Harken, at its core, is a simple product. First, there's the main app, which lets you create flashcards and review them on a spaced repetition schedule. You can put almost anything on a Harken flaschard, including rich text, images, inline code, and code blocks—no matter what you're trying to remember, Harken is here to support you. Since Harken is a responsive web app, you can create and review cards on any device. And if you're currently an Anki user, you can import all your decks and review history to Harken in just a few clicks. Lastly, Harken’s stats page turns your reviews into useful charts to help you visualize just how much you’ve remembered.


Second, there's the Harken Chrome extension. The extension is a powerful tool designed to facilitate learning from any article on the internet. By utilizing AI (specifically, GPT-4), it generates relevant questions with a single click, allowing you to assess your understanding as you read through the content. The process is simple:

  1. Open any online article.
  2. Click on the Harken Chrome Extension to generate questions about the article.
  3. Answer the questions as you progress through the article to reinforce your understanding.

You can easily add the most pertinent questions to your Harken account, which will allow you to efficiently review them on a spaced repetition schedule.


What’s the Difference Between Harken and Anki?

If you're an Anki user, one easy way to understand Harken is as a simpler, easier to use alternative to Anki. For a more detailed breakdown on the differences between Harken and Anki, you can check out this post.

The Underlying Science: How Harken Makes Remembering Easy

Harken uses a science-backed learning strategy called spaced repetition to optimize your studying, so you can learn more in less time. With spaced repetition, you’ll review unfamiliar concepts more frequently than concepts you already know. This means you’ll learn exponentially faster with Harken than with traditional study methods.

For example, let's consider how long you would need to study to remember one concept for 20 years. With traditional studying, you might review it once per week. At a timescale of 20 years, this adds up to over 2 hours of study time. But with Harken, as you get more familiar with a concept, your reviews will get more spaced out. On a spaced repetition schedule, this only adds up to about 5 minutes, a huge decrease from traditional methods.

To learn more about spaced repetition, you can check out our blog post about it, which goes into much greater detail.