Free tool
Lecture summarizer
Upload a recorded lecture, or paste its transcript, and this lecture summarizer writes what you need to revise from: an overview, the key concepts in the order they were taught, the terms the lecturer explained, and the moments in the recording to go back to.
- Free
- No sign-up
- Nothing is stored
Drop your lecture recording here, or Choose your lecture recording
Audio (M4A, MP3, WAV) or video (MP4, MOV, WebM). Up to 30 minutes of each file, 3 free files a day. The language is detected automatically.
Recording your lectures on a Mac? NoteOwl transcribes them on your Mac and writes study notes with its Student Lecture template, using on-device AI models, unlimited.
How it works
How do you summarize a lecture?
Give the summarizer the lecture: a recording from your phone, a class recording from the course site, or the transcript your university’s video platform makes. It transcribes a recording first, then writes the summary from what the lecturer said.
- 1
Add the lecture
Upload an audio or video recording (the first 30 minutes are used), or paste a transcript or caption file of up to about an hour.
- 2
Choose how much detail
Short for a quick reminder of the topic, detailed for revision notes with up to a dozen concepts and the terms defined.
- 3
Save it with your notes
Copy it into your notes app, or download it as Word, Markdown or text, next to your own notes from the class.
What does a lecture summary include?
Four parts: an overview of what was taught, the key concepts in the order the lecturer covered them, the terms the lecture defined, and the moments in the recording where each part starts.
- Overview
- What it holdsWhat the lecture covered and its main argument
- Key concepts
- What it holdsThe ideas the lecturer explained, in teaching order, each in a sentence or two
- Terms explained
- What it holdsWords the lecture itself defined, with the meaning it gave; none are added from elsewhere
- Key moments
- What it holdsTimes in the recording where each part begins, to rewatch the hard bits
| Part | What it holds |
|---|---|
| Overview | What the lecture covered and its main argument |
| Key concepts | The ideas the lecturer explained, in teaching order, each in a sentence or two |
| Terms explained | Words the lecture itself defined, with the meaning it gave; none are added from elsewhere |
| Key moments | Times in the recording where each part begins, to rewatch the hard bits |
How do you revise from a lecture summary?
Use it as a checklist, not a replacement for the class. Set it beside your own notes, test yourself on each concept, and rewatch only the parts you didn’t follow.
- 1
Compare it with your notes
Anything in the summary that isn’t in your notes is what you missed while writing.
- 2
Turn concepts into questions
Cover the summary and explain each concept out loud, then check yourself against it.
- 3
Rewatch only the moments you need
Use the times beside each part to go back to the explanation you didn’t follow.
Which lecture recordings can it read?
Audio from a phone or recorder (M4A, MP3, WAV) and video from a class recording (MP4, MOV, WebM). A video’s picture is never sent: only short pieces of its sound are transcribed, then the transcript is summarized, and nothing is stored.
For the full transcript without a summary, use the lecture transcription tool. To lay out your own notes from the class, the Cornell method puts a summary at the bottom of every page.
Can a Mac record a lecture and write the study notes?
Yes, with NoteOwl. It records the lecture in the room or from an online class, transcribes it on your Mac, and its Student Lecture template writes the main topics, key concepts and definitions, and anything flagged for the exam, with on-device AI models. See NoteOwl as a lecture recorder.
FAQ
Questions about summarizing lectures
Is the lecture summarizer free?
Yes. It summarizes 3 uploaded recordings a day, up to 30 minutes of each, and 5 summaries a day in all, with no account and no app to install.
Can it summarize a lecture longer than an hour?
An upload is summarized from its first 30 minutes. A pasted transcript can run to about an hour of speech; for a longer lecture, summarize it in two halves, or paste the part you need.
Where do I get a lecture’s transcript?
Many lecture video platforms make one: look for a captions, transcript or CC option beside the recording, and download it as a text, VTT or SRT file. Paste it, or open the file on this page.
Will it add facts the lecturer didn’t say?
It is told to write only what the lecture says, and the server checks the summary against the transcript before you see it. A term the lecture never used, or a figure it never gave, is removed.
Does it work for lectures in other languages?
Yes. A recording’s language is detected from the speech, and the summary is written in the same language as the lecture.
Can I use it for recorded seminars and talks?
Yes. Anything taught out loud works the same way: a seminar, a guest talk, a tutorial or a revision session. The key concepts and the moments come from whoever is speaking.
Keep exploring
More summary tools
- Podcast summarizerUpload a podcast episode or paste its transcript and get the episode in brief, the topics, word-for-word quotes and key moments
- SummarizerPaste an article, report, essay, email or notes and get a short, medium or detailed summary and the key points; nothing is stored
- Video summarizerUpload a video or paste its transcript and get an AI summary, the key points and key moments with times; nothing is stored
- YouTube video summarizerPaste the transcript under a YouTube video and get a summary, the key points and key moments with its timestamps; never contacts YouTube
Related
- Lecture recorderRecord lectures in the room through your Mac’s microphone, in an online class with no bot, or from a file, then turn them into study notes
- Lecture notes templateA template to copy for study notes from a lecture: topics, definitions, examples and exam points, with an example, and how NoteOwl writes it
- Cornell notesThe Cornell note-taking method: the cue column, notes and summary, the five steps, a template to copy, an example, and how it fits a recorded lecture
- Lecture transcriptionTranscribe a recorded lecture or class free in your browser, with times, ready to turn into study notes; nothing is stored
Every lecture, turned into study notes on your Mac
Free to download. Runs entirely on your Mac.
macOS 26 or later · Apple Silicon (M1 or newer) · 16 GB memory minimum, 24 GB recommended
About NoteOwl
NoteOwl is private AI meeting notes and memory for the Mac. It captures meetings without a bot joining the call, labels every speaker, writes summaries and action items, and builds a memory of every conversation that you can chat with — fully offline, because the speech recognition and the AI run on the Mac itself. Dictation into any app is free; Pro is a one-time purchase.
NoteOwl pricing: what’s free and what Pro adds
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