Keeping it private
AI journal privacy: what happens to your voice
Where your recording goes when a voice journal transcribes it, the three ways apps keep or delete audio, and how to read a privacy policy in five minutes.
In this guide
- Is your voice journal private?
- Where does your recording go when an app transcribes it?
- Do voice journal apps keep your recordings?
- Is the AI trained on your journal entries?
- How do you read a journal app’s privacy policy in five minutes?
- What else keeps a voice journal private on your phone?
- What does Dearly do with your voice?
- What does Dearly give up for this?
- A checklist you can copy
Is your voice journal private?
Only if its privacy policy says where your recording goes after you stop talking, and for how long. Most store listings say “private” or “secure” and stop there.
Every AI voice journal app will tell you it’s “private” or “secure”. Almost none will tell you, in the store listing, the one thing that matters: after you stop talking, where is the recording, and for how long?
A diary is the most sensitive thing most of us will ever put on a phone. A voice diary adds one more thing: your voice, with its hesitations and its timbre. A voice identifies you in a way a password can’t, and unlike a password it can’t be changed. Before you trust an app with it, you deserve a straight answer. This guide explains what actually happens to your voice, the three models apps use, how to find out which one you’re looking at, and what we do in Dearly.
Where does your recording go when an app transcribes it?
To turn speech into text, something has to run a speech-recognition model over your audio. There are only two places that can happen:
- On your phone. The model runs locally. Your audio never leaves the device. This is the most private option, and also the most limited: on-device models are smaller, handle accents and background noise worse, and are often tied to specific hardware (Google’s Recorder app is Pixel-only for exactly this reason).
- On a server. Your audio is sent to a transcription service, converted, and the text comes back. Better accuracy, works on any phone, and the privacy question becomes: what does the server do with the file once it has the text?
Anything labelled “AI insights” (summaries, mood, patterns) is almost always server-side too, but it runs on the text of your entries, not on your audio. Those are separate questions, and a good policy answers both.
Do voice journal apps keep your recordings?
It depends on the app, and there are only three answers: uploaded and kept, uploaded and then deleted, or never uploaded. Which one an app uses should be written in its policy.
1. Uploaded and kept
The app stores your recordings in its cloud, usually so you can play them back later and sync across devices. Day One works this way (with end-to-end encryption, which is the best version of this model). The trade-off is permanent: your voice exists on someone else’s infrastructure for as long as your account does, and the app’s breach surface includes your audio.
2. Uploaded, then deleted
The recording is sent for transcription, the text comes back, and the audio is deleted from the server, immediately or within a stated window. AudioPen states this explicitly; so does Dearly. This is the practical middle: server-grade accuracy without long-term audio retention. The things to check are whether “deleted” is stated in the policy (not just the marketing) and whether a third-party transcription provider is named.
3. Never uploaded
Fully on-device. The most private and the rarest, because it constrains accuracy and hardware. If an app claims this, it should also work in airplane mode. That is the easy test.
Is the AI trained on your journal entries?
Separate from audio, ask what happens to your text. Some services reserve the right to use your content to improve their models. For a diary that should be a hard no. Look for a plain sentence: “we do not use your content to train AI models.” If the policy doesn’t say it, assume it isn’t promised.
How do you read a journal app’s privacy policy in five minutes?
Search the policy (Ctrl/Cmd-F) for these words and read the sentence around each:
| Search for | You’re looking for |
|---|---|
| ”audio”, “recording”, “voice” | Is audio stored? For how long? Where? |
| “delete”, “retain”, “retention” | A stated window, not “as long as necessary" |
| "train”, “improve our models” | An explicit promise that your content is not used for training |
| ”third part”, “processor”, “provider” | Who actually runs transcription and AI; they should be named |
| ”encrypt” | In transit (the minimum) and ideally at rest |
| ”export”, “delete your account” | Can you take everything out and remove everything, from inside the app? |
If a five-minute search can’t answer the audio question, that is itself the answer.
What else keeps a voice journal private on your phone?
Three things a policy won’t cover: a lock on the journal itself, reminders that don’t show your entries, and analytics that never see them.
- A lock. Biometric lock (Face ID, Touch ID, fingerprint) on the journal itself, not just the phone. Your phone gets handed to people.
- Notifications that don’t leak. A reminder that previews your last entry on the lock screen undoes the lock.
- Analytics scope. Usage analytics are normal; your entries should never be in them. The policy should say what the analytics vendor receives.
What does Dearly do with your voice?
Dearly sends your recording over an encrypted connection to be transcribed, and never stores it on a server. Here is the rest, in the same terms:
- Your recording stays on your phone. It travels over an encrypted connection only to be transcribed, and is never stored on a server. Model #2, stated in the privacy policy, not just here.
- Transcription and insights run on Google’s Gemini, named in the policy, under paid-tier terms that don’t let Google use your content to train its models. Dearly doesn’t use it for training either.
- Only the transcribed text syncs, so your journal is on your other device but your voice isn’t.
- Biometric lock is in the free tier.
- Analytics are named and kept away from your entries. Firebase Analytics and Crashlytics, both disclosed in the policy, with the advertising ID disabled. Your transcripts, audio, moods and notes are never in an analytics event or crash report.
- Export and permanent deletion are inside the app. Delete account removes your synced data, your account, and the recordings and database on your phone. If you’ve already uninstalled, there’s a web flow: how to delete your account.
What does Dearly give up for this?
Server transcription means Dearly needs a connection to turn a recording into a page. Recording works offline, and the page appears when you’re back online.
A fully on-device pipeline would be more private still, because no audio would travel at all. On most Android phones today, though, on-device speech recognition is noticeably less accurate with natural, unscripted speech, which is exactly what a voice journal is made of. A journal that mishears you gets abandoned. Sending audio over an encrypted connection and never storing it is the balance Dearly chose, and the privacy policy says so in plain language. If that trade-off doesn’t work for you, that’s a fair call to make before you start, not after.
A checklist you can copy
Before trusting any AI voice journal:
- Does the policy say whether audio is stored, and for how long?
- Does it say your content is not used for training?
- Is the transcription/AI provider named?
- Can you lock the journal with biometrics?
- Can you export and delete everything from inside the app?
Five yeses is the bar. To see how 12 journal apps answer these questions, read 12 journal app privacy policies, compared. Related: best AI voice journal apps compared · the voice journaling guide.