Migrating Keychain Access secure notes to Notes app notes
What are these secure notes and how do they work?
Secure notes provide a protected location to store potentially-sensitive information, and are a longstanding feature of Keychain Access app. These notes are stored in the keychain files present on macOS.
This secure note feature does not exist on iOS or iPadOS.
The Keychain Access User Guide for macOS 15 Sequoia specifically points to using Notes app for secure notes, where previous versions referenced the secure notes feature within Keychain Access app:
Store confidential information securely using Notes on Mac - Apple Support
Starting in macOS 15 Sequoia, Keychain Access app can read but no longer create Secure Notes.
Password app also uses a different and more secure storage, and which apparently doesn't include a generic text note feature.
Per Apple, the file-based keychains are fading away, with a migration to the data protection keychain underway. (Which can use biometrics and the secure enclave, where the file-based keychains cannot.)
Related: TN3137: On Mac keychain APIs and implementations | Apple Developer Documentation
TN3137 contains the following statement: "The file-based keychain is on the road to deprecation. It’s not officially deprecated, but some of the APIs surrounding it are. For example, SecKeychainCreate was deprecated in the macOS 12 SDK. Moreover, new features, like iCloud Keychain, require the data protection keychain."
Keychain Access app is the path into the file-based keychains.
Password app is the path into passwords and into the newer (and more secure) keychains, starting with macOS 15, iOS 18, and iPadOS 18.
How to migrate your existing secure notes?
This transition means that you will be opening your existing secure notes using Keychain Access, and copying the text contents (⌘A⌘C) and pasting into newly-created Notes app notes (⌘V).
This copy and paste, and the deletion of any unnecessary apps, can happen over time.
Exactly when the file-based keychains — and any secure notes will be removed is not known.
Feedback for Apple?
Got comments or suggestions about this? Log your feedback with Apple either via Feedback Assistant for third-party developers, or for non-developers via Apple Product Feedback.