How to turn a lecture into notes on iPhone

There are two ways to sit in a lecture. You can type everything the professor says and understand none of it, or you can listen and understand and have nothing to revise from. A recording that turns itself into notes is the way out of that choice.

This guide is for students. It shows how to record a lecture on iPhone with Memo, a free app for iOS 26 or later, and get a transcript, a summary and a to-do list back. Memo was built for exactly this; one of our App Store reviews puts it better than we can: “I don’t even stress about taking notes anymore, I can actually listen to the prof and understand stuff.”

First, check the rules

Many universities allow recording lectures for personal study and some require you to ask the lecturer. Ask once at the start of the term. Most say yes, and a few will give you the slides as well. Never share a recording of a lecturer without permission; sharing your own notes is a different matter.

Step 1: record from the front third of the room

Open Memo and tap the record button. Memo keeps recording when you lock the phone, so it can sit in your pocket or on the desk.
Pick the engine. On-device AI keeps the audio and the notes on your iPhone and works without a connection, which matters in a lecture hall with no signal. Cloud AI works on every iPhone and in more than 99 languages, and uploads the audio after the lecture.
Sit where you can hear clearly. A phone hears roughly what you hear, so the front third of the room gives a clean recording and the back row gives echo.

A 90-minute lecture on the free tier: On-device AI has no limit beyond the phone’s storage. Cloud AI on the free tier accepts up to 30 minutes per recording and a daily allowance, which is enough for a seminar but not a full lecture; Memo Pro lifts the limits. On iPhone 15 Pro and later, and every iPhone 16 and 17, On-device AI is the natural choice for lectures. Which iPhones support it has the full list.

Step 2: what you get back

When you stop, Memo writes:

A transcript with timestamps. Tap a line to hear the professor say it again, which is the fastest way to check a formula or a name you did not catch.
A summary with a title, the key points and, for a lecture, the structure of the argument.
A to-do list: “read chapter 4 before Thursday”, “the essay question will be on the second half”, “office hours moved to Tuesday”. Lecturers say these things once, in passing, and this is where they end up.
A chat that answers questions from the lecture.

Step 3: revise with the chat, not the recording

Nobody replays a 90-minute recording. Ask instead:

“Explain the three causes the professor gave, in order.”
“What did she say would be on the exam?”
“Give me five practice questions from this lecture.”
“Define every term she introduced today.”

The answers come from your recording only, so if the professor did not say it, Memo does not know it. For a course, that is the right behavior: you are revising what was taught, not what the internet thinks about the topic.

Step 4: build a course, not a pile

One folder per course. Memo keeps memos in folders. “Poli sci 201” with a memo per lecture becomes a searchable term in a month.
Attach the slide photo. Take a picture of the board or the slide during the lecture and attach it to the memo. The transcript says “as you can see here”; the photo shows what “here” was.
Import the recordings you already have. If you recorded earlier lectures in Voice Memos, share them to Memo and they get the same transcript and summary. Import an audio file explains the share sheet route.
Export before the exam. Copy the summaries into one document, or print the transcript of the lecture you are least sure about. Export a memo has every option.

Languages

If your lectures are in a language other than English, Cloud AI transcribes more than 99 languages. On-device AI follows the languages Apple supports on the device for speech recognition and Apple Intelligence, and Memo checks this when you choose the engine. Our guide Voice memos to text in 99+ languages explains which engine to pick for which language.

A note on accuracy

A transcript is a tool, not a transcript of record. Names of people and places, formulas and specialist vocabulary are the words most likely to come out wrong, because they are the words the model has heard least. The timestamp on every line exists so you can check the original in two seconds. For anything you would be graded on, check.

The short version

Record from the front third of the room with On-device AI, listen instead of typing, and revise from the summary and the chat. The recording is your safety net; the summary is your notes; the to-do list is the part you would have missed.