Caption: Capture runs on your device by default. Optional polish is opt-in.
My friend Sarah is a therapist. She records session notes between clients — observations, patterns, follow-up items. Nothing that identifies patients directly, but still sensitive enough that she needs to be careful.
She tried a popular transcription app last year. Beautiful interface. Instant transcripts. She used it for two months before she read the privacy policy closely.
Every recording was being sent to the cloud for transcription. The company promised they weren't training AI on user data, but the audio was still hitting their servers. And once it's on someone else's server, you don't control it anymore.
She deleted the app immediately and asked me what to use instead.
That conversation is why privacy is the default in Brain Dump, not an upgrade feature.
The question nobody asks until it's too late
When you record a voice note, where does the audio go?
Most people assume it stays on their phone. But with many transcription apps, the audio gets uploaded to a server for processing. The transcription happens in the cloud, the text comes back to your phone, and the audio... who knows.
Maybe it's deleted immediately. Maybe it's kept for 30 days for "quality improvement." Maybe it goes into a training dataset for the next AI model.
You don't know. And that's the problem.
How Brain Dump handles your data by default
Transcription runs on your device. When you speak into Brain Dump, Apple's on-device speech recognition converts your voice to text. The audio never leaves your phone. No upload. No server. No third party processing your words.
Notes save to your iCloud, not ours. The text file gets saved as a Markdown file in your Brain Dump folder in iCloud Drive. That's your iCloud account, not a database we control. You can open it in Files, Obsidian, VS Code, any text editor.
We don't see your notes. Because files live in your iCloud, we have no access to them. No database storing your thoughts. No analytics tracking what you write about. Your notes are yours.
This isn't a privacy mode you have to enable. It's how the app works by default.
A day in the life of your voice note
Here's what actually happens when you record:
- You open Brain Dump and tap record.
- You speak for a minute about whatever's on your mind.
- Your iPhone converts audio to text using the Neural Engine — the same chip that processes Face ID.
- The app writes a Markdown file to
iCloud Drive/Brain Dump/[filename].md. - If you're online, iCloud syncs the file to your other devices. If you're offline, it syncs later.
At no point does the audio or text leave your device unless you explicitly choose a polish feature.
When polish changes the equation
Brain Dump has optional AI features: summary, action items, rewrite. These can clean up a messy brain dump or extract key points.
These features are off by default. You have to enable them in settings. And even then, they only run when you tap a polish button.
When you use polish:
- The text content of that specific note gets sent to an AI provider (you can choose which one in settings).
- The AI processes it and returns polished text.
- You can delete the polished version if you don't want it.
The important part: you choose when this happens. It's never automatic. And the raw capture never goes through AI — only the text you explicitly ask to polish.
Why Sarah switched
Sarah needed three things:
-
Confidence that session notes stayed private. On-device transcription meant patient observations never hit a server.
-
The ability to use it offline. Between clients, she doesn't always have reliable wifi. Airplane Mode transcription means she can capture notes anywhere.
-
Control over her data. Files in her iCloud meant she could back them up, move them, delete them. No company holding her notes hostage.
Brain Dump gave her all three. She's been using it for a year now, and the privacy model hasn't changed. What was private on day one is still private today.
The questions people actually ask
"Can't Apple still see my data since it's in iCloud?" Your iCloud data is encrypted. Apple has your encryption keys for standard iCloud (they need them to help if you forget your password), but they're not reading your notes. If you want even stronger guarantees, enable Advanced Data Protection in iCloud settings — that removes Apple's ability to decrypt your data.
"What if I want to use AI polish sometimes?" Use it. That's why it exists. Just know that when you press that button, that specific note's text gets sent for processing. You're making an explicit choice to trade privacy for convenience in that moment.
"How is on-device transcription possible?" Apple ships speech recognition models on the iPhone itself starting with iPhone 12 and iOS 15. The Neural Engine is fast enough to transcribe in real-time. No cloud needed.
"Is Airplane Mode transcription really accurate?" Yes. I've tested it side-by-side with cloud transcription. Same accuracy, zero latency from network hops, complete privacy. See offline capture guide for details.
"What happens if Brain Dump shuts down?" Your notes are Markdown files in your iCloud. The app could disappear tomorrow and you'd still have every note. Open them with any text editor, Obsidian, VS Code, whatever. No lock-in.
Why we built it this way
We could have made an easier product. Send everything to the cloud, transcribe on servers we control, offer unlimited polish features, store everything in a database.
But that would mean:
- You'd have to trust us with your notes
- We'd have to secure a database full of people's private thoughts
- You'd be locked into our ecosystem
- Your notes would be vulnerable if we got hacked
File-based, on-device transcription is harder to build. But it's the right architecture for a tool that holds your thoughts.
You shouldn't have to choose between convenience and privacy. With modern iPhones, you can have both.
The privacy promise
Brain Dump defaults to on-device everything:
- Transcription happens on your iPhone
- Notes live in your iCloud, not our database
- Audio never leaves your device during capture
- Optional polish is off until you turn it on
If you want to verify this yourself:
- Put your phone in Airplane Mode
- Record a voice note in Brain Dump
- Watch the text appear instantly
If it works offline, it's not hitting a server. That's the simplest privacy test.
Learn more:
- Privacy Policy — The legal version of this article
- Plain text vs databases — Why files beat proprietary storage
- Offline capture guide — How to use Brain Dump without internet
Download: Brain Dump on the App Store — Privacy by default, polish when you want it.