What Happens to What You Add: Sync, Storage and AI, Explained

When you hand something to an app, you are making a quiet bet about where it goes. The photo of the contract, the voice note after a difficult call, the message with the door code: a second after you save it, it is somewhere. The question is where, and who else could read it.

Privacy pages often answer with reassurance ("secure," "encrypted," "private"). Those words hide the two questions that actually matter:

1. Where does it live? Only on your device, or also on the company's servers?
2. Who holds the keys? Is it encrypted so that only your devices can read it (end-to-end), or so that the company can also decrypt it when its systems need to?

A third question has become just as important: what does the AI see?

This guide answers all three for the popular note apps, and for YAFOY, without the reassurance.

Local-only storage is the most private, and the most fragile: lose the phone and you lose the notes.

Cloud storage with standard encryption protects data in transit and on the servers, but the company holds the keys. That allows search on the server, AI features and account recovery, and it means the company could technically access your data.

End-to-end encryption means only your devices hold the keys. The company can't read your data, and usually can't recover it if you lose your password. It also makes server-side features, including most AI, harder or impossible.

No option is "right." Each is a choice between convenience, recoverability and privacy.

Apple Notes syncs through iCloud. With standard data protection, notes are encrypted in transit and on Apple's servers, and Apple holds the keys. Turn on Advanced Data Protection and Notes becomes end-to-end encrypted, with keys only on your trusted devices. Locked notes are end-to-end encrypted either way, and Apple can't help if you forget the password.

Google Keep syncs to your Google account. Google says it encrypts data in transit, and it doesn't offer end-to-end encryption for Keep. If you choose to connect it, Gemini can create and show your Keep notes.

Notion encrypts data in transit (TLS 1.2+) and at rest (AES-256). It isn't end-to-end encrypted. By default, Notion and its AI providers don't use your data to train models.

Evernote uses TLS in transit and lets you encrypt selected text inside a note with a passphrase it never stores, but not whole notes, files or images, and only in its desktop and web apps.

Obsidian stores notes as files on your own device. Its optional Sync service ($4 a month billed annually) is end-to-end encrypted by default. When the same note changes on two devices, Obsidian merges the text; for other files, the last change wins.

Day One, the journaling app, uses end-to-end encryption by default for new journals on iPhone and Mac.

YAFOY splits your data deliberately.

Your inbox isn't backed up to YAFOY. The messages in your Universal Inbox are stored on your phone, not backed up to YAFOY's servers. (Your email and chat services keep their own copies, as always.)

What you add is backed up. Things you save through Add (photos, documents, links, notes, voice notes) are the one part of YAFOY that's backed up to your account. The idea is simple: these are the things you chose to keep, so they should survive a lost or replaced phone. Voice audio and transcripts are kept in your private storage.

It syncs, simply. Saved items stay in step across your devices. If an item is edited in two places, the newest edit wins. Deletions sync too, as small records ("tombstones") that tell your other devices an item was removed, so it doesn't reappear.

It is not end-to-end encrypted. Your saved items are stored in your private account, but they aren't encrypted in a way that only your own devices can read. If end-to-end encryption is essential for a particular note, Obsidian Sync, Day One, or Apple Notes with Advanced Data Protection are better homes for it.

What the AI sees. When you add something, YAFOY analyzes it on your device first and redacts content before sending it to AI, which returns a title, summary, people, topics and deadlines. Those results feed Memory, and the deadlines feed Insight. Memory's Ask answers only from what you saved. No redaction is perfect, so keep passwords, ID numbers and bank details out.

Videos aren't uploaded. YAFOY understands a video from a still frame plus its filename and length; video files over 10 MB are skipped.

	Where notes live	End-to-end encrypted	Published conflict rules	AI and your data
Apple Notes	iCloud and devices	With Advanced Data Protection; locked notes always	Not documented	Apple Intelligence features on supported devices
Google Keep	Google account	Not offered	Not documented	Gemini can access Keep if you connect it
Notion	Notion's cloud	No (AES-256 at rest)	Not documented	Not used for training by default
Evernote	Evernote's cloud	Selected text only	Not documented	AI on by default; can be turned off
Obsidian	Your device; optional Sync	Sync: yes, by default	Text merged; last change wins for other files	No built-in AI
Day One	Device and Day One sync	Yes, by default for new journals	Not documented	Optional AI on paid plan
YAFOY Add	Your account (inbox stays on device)	No	Newest edit wins; deletions sync	On-device first, redacted before AI

As of October 2026.

YAFOY's choice is a middle path: your inbox isn't backed up to our servers, and the things you deliberately keep are backed up so you don't lose them, synced so they're everywhere you are, and deletable whenever you like. It isn't the most locked-down option, and we'd rather tell you that than imply otherwise. See how Add and Memory work →

Try YAFOY free knowing exactly where your things go.