The reader that quizzes you

Read a PDF, article, or video with AI beside you. Winda writes flashcards and quizzes from it, each linked back to its source, and brings them back on a schedule.

Why spacing beats cramming

The spacing effect is one of the most robust findings in memory research: reviews spread out over time produce far stronger retention than the same reviews massed together — yet most study habits ignore it entirely.

The reason turns out to be retrieval. Each time you pull a fact back out of memory, just before you would have forgotten it…

That single observation is the basis of every spaced-repetition system today. The trick is not to review more, but to review at the right moment: just before you would have forgotten.

Read with AI beside you

Select any sentence and the reading assistant explains it in place, translates it, chats about it, or turns it into a flashcard or a quiz.

In experiments published in 1885, Hermann Ebbinghaus memorized long lists of nonsense syllables, then measured how much he kept as the hours and days went by. The result was the forgetting curve: a steep drop in the first day, then a slow, grinding decline.

ExplainRetention falls fastest right after learning. More than half is gone within a day, and then the curve levels off. Every review lifts the curve and slows the next drop.

The brain treats a fact it meets once as noise. Read a chapter, sit through a lecture, finish an article, and the ideas feel solid in the moment, yet a few days later only fragments remain.

Annotation

An explanation or a translation, opened under the sentence it belongs to and kept there for you to come back to.

Chat

Ask about the whole document or the text you selected.

Questions written from your material

Winda writes flashcards and quizzes for you. Edit any of them before they go into your reviews.

From anything you save

Web pages, PDFs, YouTube videos and images, saved with the browser extension. Winda writes questions from a whole document at once.

From a selection

A sentence or a passage you select in the reader.

From the chat

A reply in the chat beside the page.

Practice on a schedule

Each card comes back right before you'd forget it. Answer it well and the gap grows; miss it and it comes back sooner.

✓ right

✗ missed

Start with a deck

Browse all 19 decks

Free practice decks for exams, programming, languages and science, every question with its source. Try one in the browser, or save a copy and practice on a schedule.

A reader that helps you remember.

Bring what you are studying. Read it with AI beside you, and let the questions come back to you on a schedule.