Free for students · Philippines & worldwide

Highlight anything.
Cassie explains it.

Your AI study buddy for readings, homework and reviewers, on any website, PDF, slide deck or photo. She explains the why, so it actually sticks.

Start free
No account needed Your notes stay on your device Phone, web & Chrome
Labs

29 labs. Play with it, then ask why.

Cassie’s Labs: simulations, 3D models and daily puzzles, from biology to space
The solar system in 3D: the planets where they really are todayEarth up close: real NASA maps, clouds and oceans that catch the sunSaturn and its ringsJupiter and its stripes of cloudMars, the red planet
Cassie’s Labs on a phoneThe human body in 3D on a phoneEarth in the 3D solar system on a phone
Your study shelf

Your lessons, all in one place.

Readings, slides, PDFs and photos of your notes. Cassie reads them all, diagrams too, and keeps your reviewers, flashcards and mistakes together.

Every page you read,

Every cell in your body needs energy. It gets it through cellular respiration.

one buddy beside you.

  1. Highlight
  2. Explain
  3. Quiz
  4. Remember

One buddy. Every subject.

From nursery rhymes to calculus: explained at your level.

From reading to remembering.

Follow one word through Cassie.

Reading
cellular respiration

Cassie’s brain

She shows the why, step by step, not just the answer.

You askx² − 2x − 3 = 0
Factorthinking…
She answersx = 3 or x = −1with a graph you can draw on
Try it

Highlight a word. Right here.

This page works like a lesson in Cassie. Select any word, or tap a bold one, and ask her to explain it, quiz you on it, or make a flashcard.

Try it: highlight any word, or tap a bold one

Energy in cells

Lesson 3.2 · page 14

Every cell in your body needs energy. It gets it through cellular respiration: inside the mitochondria, glucose from your food reacts with oxygen to make ATP, and you breathe out the carbon dioxide that’s left.

Plants run it the other way. With the chlorophyll in their leaves, they use photosynthesis to turn carbon dioxide, water and sunlight into glucose, and the oxygen you breathe.

This is how Cassie works on any website, PDF, slide deck or photo of your notes.

The main things

Don’t watch a demo. Use it.

Every tab is a working piece of Cassie. The Labs, 3D space, atlas and puzzles are the real ones from the app, running right here.

In the app she answers anything. These demos are written ahead.

Meet Cassie

She shows you what she’s doing.

Cassie is a cursor with feelings. While you study, she reads, thinks, searches and celebrates with you, so you always know what’s happening.

Tap Cassie to poke her.
Everything else

Small things that add up.

Go on. Every card works.

Flashcards that come back

Tap to flip. Cassie brings each card back right before you’d forget it.

Export to Anki or Quizlet any time

Quiz me

On your lesson, your file, or what you got wrong last time.

Photosynthesis gives off…

Focus timer

25/5, 50/10, or your own rhythm.

25:00

At your level

The same idea, explained for whoever’s asking.

Photosynthesis turns light energy into chemical energy. In the chloroplasts, chlorophyll captures light to combine carbon dioxide and water into glucose, releasing oxygen: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.

Research with real sources

Real papers, organized. Then cite them in any style.

Walker, M. P., & Stickgold, R. (2004). Sleep-dependent learning and memory consolidation. Neuron, 44(1), 121-133.

Draw together

A shared board with your classmates, share a code and sketch it out.

Mika is here

She remembers. You decide

What Cassie remembers stays on your device. Forget anything with a tap.

  • You’re in Grade 10, Section Rizal
  • Fractions trip you up a little
  • Biology exam on Friday
  • You like examples with basketball

Student or working

Cassie dresses for the job: reviewers for school, reports and emails for work.

Let’s turn chapter 4 into a reviewer with 10 practice questions.

Always in sight

Cassie’s Island shows what she’s doing, even while you read something else.

Reading Module 6.pdf · page 4 of 18

Made for learning, not for test time.

Cassie explains the reasoning, quizzes you, and turns your lessons into reviewers. She’s for readings, homework and review, not for use during a test or quiz.

Because the point isn’t the answer. It’s you knowing it.

Private by design

Your notes are yours.

Account optional

Use Cassie without signing up. Make an account and only your profile, settings and saved quiz mistakes sync. Never your chats or files.

On your device

Chats, memory and reviewers are saved in your browser, export a backup any time.

Bring your own key

Power users can plug in a free Groq or Gemini key for unlimited use on the free plan.

Pricing

Pasado ka dito.

Free forever, no card needed. When you want more, one payment covers your whole semester.

Free

See what Cassie can do. Best for trying it out.
₱0forever
No card needed
Start free
  • 20 questions a day: chat, quiz & highlight
  • Reviewers from your PDFs, slides & Word files
  • 20 quick pictures a day, plus 3 Gemini pictures a week
  • Reads photos, diagrams & handwriting
  • Save chats as Word, PDF or image
  • Explore 3D: the human body (all 10 systems, boy & girl), cells, the solar system & the globe, 2 free views of each a week
  • Talk with Cassie by voice: Bella’s studio voice while this month’s lasts, then Cassie types her answers
  • Quiz me, Review my mistakes & Teach Cassie
  • Labs: every simulation, puzzle, game & study tool, plus Real 3D twice a week in each lab
  • Board, graphs, focus timer, memory & sync
  • Chrome extension: highlight, snip, Teach me & ask about any page
  • Research with real papers & citations
  • Unlimited with your own free API key
Best for school

Plus

Five times the questions. Best for everyday school.
Pasado Pass
₱599/ semester
about ₱4 a day
Join the waitlist

One payment for 5 months. Never renews. 7 days to change your mind.

  • Everything in Free, including the Finals Reviewer Kit (your files become reviewers, quizzes & flashcards), an exam plan and your weekly progress card
  • 100 questions a day
  • 100 answers a day from Cassie’s smarter model (Free gets 10)
  • 5 Gemini pictures a day
  • All the 3D, any time: the body, cells, solar system, globe & Real 3D labs, plus the Museum quiz
  • Save & print: boards as PDF, Cornell notes & reference lists
  • Up to 5 exam plans at once, and plans from your notes

Pro

The most of everything, and the smartest answers. Best for finals season.
₱1,999/ semester
about ₱13 a day
Join the waitlist

One payment for 5 months. Never renews. 7 days to change your mind.

  • Everything in Plus
  • 150 questions a day
  • 15 answers a day from Cassie’s smartest model, then 100 from the smarter one
  • 20 Gemini pictures a day

₱599 for the whole semester: about ₱4 a day, less than one hour with a tutor.

Daily limits start again at midnight, Philippine time, and weekly ones on Monday. They are for one person studying, not shared accounts or automated use. Paid plans are launching soon. Everything on Free works today.

FAQ

Questions, answered.

What is the Pasado Pass?

It’s Cassie Plus for your whole semester: 5 months for one payment of ₱599. It never renews, so nothing is charged when it ends, and we tell you in the app and by email about a week before it does. If it isn’t for you, email [email protected] within 7 days of paying and you get all of it back, no questions asked.

Is Cassie really free?

Yes, forever, with no card needed: 20 questions a day, 20 quick pictures a day and 3 Gemini pictures a week, plus a taste of the 3D (2 views of each a week) and talking with Cassie. If you add your own free Groq or Gemini key, you can use Cassie as much as you like.

What can she read?

Any website you highlight or snip, PDFs, PowerPoint and Google Slides, Word files and Google Docs, and photos or screenshots of your notes, including the diagrams and graphs in them.

Does it work on my phone or tablet?

Yes. Open Cassie in your browser and add it to your home screen. For PDFs, Word and PowerPoint, attach the file and tap 📖 Read & highlight: read it inside Cassie and highlight any part. In other apps: on Android, select the words → Share → Cassie. On iPhone and iPad, set up the one-time “Ask Cassie” Shortcut (steps in Cassie → Settings → Use Cassie in other apps). Screenshots and photos of your notes work too. The on-page popup and snipping on a computer come with the Chrome extension.

How do I add Cassie to Chrome?

Download the Cassie extension, then unzip it. Open chrome://extensions, turn on Developer mode (top right), click Load unpacked and pick the cassie-extension folder. Pin Cassie from the puzzle-piece menu and you’re done. No key needed. Works in Chrome and Edge on a computer.

Where do my notes and chats go?

They’re saved in your own browser, not on our servers. Your question and any file you attach are sent to the AI service to get an answer, and that’s it. If you make an account, these sync so you have them on every device: your profile, settings, saved quiz mistakes, flashcards, exam plans and your weekly study counts. Your chats stay on your device. You can export a backup or clear everything at any time.

Can I use Cassie during a test or quiz?

No, and please don’t. Cassie is built for studying: understanding readings, practising, and making reviewers. Using her during a graded test or quiz isn’t what she’s for.

How do I pay from the Philippines?

When paid plans launch, you’ll pay through Lemon Squeezy, Cassie’s payment partner, with a debit or credit card, Google Pay or Apple Pay. GCash and Maya aren’t offered yet; if that changes, this answer will say so. Everything on Free works today with no card.

Study with Cassie tonight.

Free, private, and ready on any page you’re reading.

Open Cassie. It’s free