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Synapsi
New: the Feynman test, graded by AI

You think you know it
until you explain it

Drop in any lecture, PDF, or video. Synapsi builds the study kit, then makes sure it sticks: an AI grades how well you explain it back, and spaced repetition drills the gaps.

7 days of full access · no credit card
The real test of understanding: can you explain it in plain words?
That’s what the Feynman technique trains. Synapsi grades it on every note.
What it does

Not just notes. Proof you learned them.

Feynman teach-back, judged by AI

Explain it back in plain English. Synapsi judges what you actually understand, surfaces the gaps, and writes cards for them.

Real spaced repetition

An SM-2 schedule brings each card back right before you'd forget it, so the gaps actually close and review takes minutes.

Quiz yourself first

Auto-generated questions from your own lecture. Find the gaps while they're still cheap.

Chat with your notes

Ask your lecture anything. Answers come from your transcript, not the open internet.

Record any lecture

Hit record on your laptop. Synapsi keeps transcribing for hours, even if you switch tabs.

AI writes the notes

A clean, structured summary built straight from the transcript. Ready before you stand up.

Mind maps, drawn for you

Every concept in the lecture and how they connect, laid out as a map you can explore.

Share with one link

Send a read-only link to your study group. Nobody needs an account to read it.

How it works

Capture → understand → prove you know it

01

Capture

Record, upload a PDF, or paste a YouTube link.

02

Generate

AI builds a summary, mind map, flashcards, and quiz in ~60 seconds.

03

Study

Real SM-2 spaced repetition. Chat with your notes.

04

Prove it

Feynman teach-back: explain it cold, an AI finds what you only thought you knew.

Everywhere you study

On web, iPhone, iPad, Mac & Android

One subscription unlocks Pro on every device you sign in on. Your notes sync automatically.
Free tools

Try it free, no signup

Pricing

Every feature free for 7 days. Pay only when you need more.

Free
$0to start
7 days of full access, no card. Reviews stay free after.
  • 7 days of full access to start, no card
  • Keep every note you made
  • Keep reviewing flashcards & quizzes
  • Create more notes with credits
  • Web + mobile
POPULAR
Pro
$4/ mo$11.99/mo
Billed $48 a year. Save 67%.
  • Unlimited lectures + notes
  • AI chat, Feynman test & mind-map expand
  • 50 MB uploads, full-depth kits
  • Unlimited flashcards & quiz
  • Priority email support
Lifetime
$199one-time
Pay once. Yours forever.
  • Everything in Pro
  • All future features
  • Founder badge
  • No subscription to manage
  • Refundable for 30 days
No subscription? Buy lecture credits from $0.45/lecture and pay only for what you study.
FAQ

Things students ask

They make the study material. Synapsi checks you actually learned it. After the summary and flashcards, a Feynman teach-back has an AI judge whether you really understand each concept, and real SM-2 spaced repetition keeps the gaps in rotation. Most apps stop at 'here are your notes.'

Ready to ace your next exam?

No card. 60 seconds to your first note.