Bring anything.
Ritsu turns it into a lesson.
A PDF, slides, a Word doc, a YouTube video, a web article, a photo of a page — Ritsu reads them all, one at a time, and turns each into a learning path.
The core move
Drop it in. Any of it.
The same three-second move, whatever the format.
- Drop 1
A textbook chapter.
- Drop 2
A two-hour lecture.
- Drop 3
A deck — speaker notes and all.
- Drop 4
Even a photo of a page.
Whatever the format, the same next step: a path you can actually learn from.
The gap
Your material isn’t one format. Your tools shouldn’t be either.
- The chapterPDF · 34 pagescopy-pasted, half of it
- The lecture2 hours of videoretyped, pause by pause
- The deck42 slidesquietly given up on
- The articlesomeone sent itlost in a tab
Every one is a different format — and most study tools take exactly one. So you copy-paste what you can, retype what you can't, and quietly give up on the rest.
Ritsu takes them as they are.
The source gallery
If it holds what you're learning, Ritsu reads it.
The eight formats people bring most — around a dozen in all, every one on the free plan.
PDF
Every page, even scanned ones — and math comes out as clean formulas.
PowerPoint
The slides and the speaker notes most tools throw away.
Word doc
Text, structure, and the images inside it.
YouTube
The full transcript, with timestamps you can jump to.
Web article
Any public article or doc, pulled out clean — ads and clutter gone.
A photo
Snap a printed page, a slide, or a diagram — read with vision AI.
Jupyter notebook
Code and notes together, cell by cell.
Markdown / text
Your plain notes and docs, as they are.
One source at a time — up to 20 MB — free.
Depth, not just breadth
Most tools open your file. Ritsu actually reads it.
Slide decks
A deck is more than its slides.
Ritsu pulls the speaker notes too — the part that actually explains what's on screen, and the part every other tool leaves behind.
Video
A two-hour video is more than a wall of talk.
Ritsu turns it into a transcript with timestamps, so every point knows the moment it came from.
Scanned PDFs
A scanned PDF is more than a picture.
OCR reads the text off the page, and pulls math out as real formulas, not blurry images.
After the drop
However it comes in, what happens next is the same.
Bring a PDF or a video, a deck or a photo — the moment it's in, it becomes the same thing: an ordered path of small Points of Knowledge, ready for every one of Ritsu's ~40 learning commands. The format is just the front door.
Questions
What people ask before they drop their first file.
PDF, Word, PowerPoint, Jupyter notebooks, images (PNG/JPG/WEBP), Markdown and text files, captioned YouTube videos, and public web articles — around a dozen in all.
Whatever you're studying from, start with it.
Drop in a PDF, paste a video, snap a photo of a page — and watch it become a lesson.