How macOS actually works
Why can you find a Things to-do in Spotlight but not a note from another app? One framework, opted into or not.
Core Spotlight lets an app donate its content to the system index — to-dos, notes, messages, documents held in a database rather than as files. The app describes each item (title, keywords, content) and Spotlight indexes it like anything else.
This is why Things tasks, some Notes, and certain app records appear in Spotlight despite not being files: the app opted in and donated them.
Purely a developer choice. An app storing data in a database (not files) is invisible to search unless it adopts Core Spotlight. Many do not bother, which is why a note in one app is findable and an identical note in another is not.
.mdimporter) — for apps whose data *is* files in a customformat, teaching Spotlight to read them
mdfind "kMDItemContentType == 'com.apple.corespotlight.item'"Lists items donated via Core Spotlight — often surprisingly many, from apps you did not realise participated.
It explains an otherwise baffling inconsistency: search coverage depends on each app's choices, not on a uniform rule. Two note apps, two behaviours. A file-based search tool sidesteps the whole question for anything stored as files — but genuinely app-internal data (a task with no file) is reachable only if that app donated it, by any tool. Knowing which of your apps keep data as files versus in databases predicts what you will and will not be able to find.
Apps storing data in databases must opt into Core Spotlight to be searchable. Many don't, so coverage is per-app, not universal.
A plugin teaching Spotlight to read a custom file format's contents, distinct from Core Spotlight which donates non-file items.
Everywhere keeps track of every file on your Mac — including the folders Spotlight hides and drives you have unplugged. Free for a day, then $19 once.
Download for Mac