Turn a lecture recording into notes with timestamps
Upload the recording and ask it questions. Every answer cites the exact moment in the lecture it came from. So checking means one click, not scrubbing through an hour of audio. Then quiz yourself on the same material.
Drop a document to get started
PDF, Word, PowerPoint, text, images, audio or video. Up to 20 MB and 50 pages. No account needed for your first one.
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Without an account: 1 document, up to 50 pages, kept for 24 hours. Sign up any time and it comes with you.
How it works
Upload the audio or video
Phone recording of a lecture, a downloaded seminar, a lab briefing.
CruxDoc transcribes it
The recording is transcribed and indexed by time, in the background.
Ask for what you need
A summary, the key definitions, "what did she say about the exam?" Every answer carries its timestamp.
Study it
Generate an exam-mode quiz or flashcards from the same lecture, spaced repetition included.
Why timestamps matter
A lecture summary you cannot trace is just someone else's notes. Timestamped citations keep the recording checkable: when an answer matters, a definition that will be on the exam, a date, a formula, you can jump to the moment it was said and hear it yourself.
It is the same rule the rest of CruxDoc follows: no claim without a source you can open.
Frequently asked questions
Q.01What recording formats work?
Common audio and video files (for example MP3, M4A, WAV, MP4). Upload the file and CruxDoc transcribes it and indexes the transcript by time.
Q.02How accurate are the timestamps?
Answers cite the transcript segment they came from, linked to its position in the recording. So "where did she say that?" is one click, not ten minutes of scrubbing.
Q.03Can I quiz myself on a lecture?
Yes. The same recording feeds the whole study layer: exam-mode quizzes, blurting graded against the transcript, and flashcards with spaced repetition and Anki export.
Q.04Is it free?
Your first upload needs no account. The free plan covers 10 documents, recordings included, and 100 questions a month.
Q.05How long does processing take?
Transcription runs in the background after upload. A typical one-hour lecture is ready in a few minutes, and the tray shows progress while it works.
Upload a lecture recording
Drop a document to get started
PDF, Word, PowerPoint, text, images, audio or video. Up to 20 MB and 50 pages. Free. No account needed for your first one.
Processing continues if you close the tab.
No account needed for your first document.