We make one of the three apps in this comparison, so read it knowing that. We also use the other two most weeks: Apple Notes for shared shopping lists, Obsidian for long drafts. All three are good tools, and none of them is “the best note app.”
They disagree about exactly one thing, and it decides everything else: who does the organizing work: you, or the software. Apple Notes gives you folders and expects you to file. Obsidian gives you links and expects you to build a system. Second Brain takes the organizing job away from you entirely, and pays for that convenience with hardware limits. Pick by which of those matches how you actually behave with notes, not by feature count. One caveat before we start: the features and prices below are what we checked as of July 2026, and all three apps change often.
Apple Notes: fast, everywhere, already paid for
Apple Notes ships with the phone, costs nothing, and starts in under a second from the lock screen. For a list you’ll need in an hour, nothing here beats it.
Its organizing tools are better than most people know. You get folders and subfolders, #tags typed anywhere in a note, and Smart Folders that collect notes automatically by tag, date, or attachment type. iOS 26 added Markdown import and export, so notes are no longer locked in a private format. On Apple Intelligence phones, search handles plain questions instead of exact keywords, and Writing Tools will proofread or rewrite what you wrote. (Writing Tools fixes your sentence but doesn’t explain the rule; we keep a plain-English grammar reference for that.) Notes even reached the Apple Watch with watchOS 26. Sharing is the quiet superpower: a grocery list both of us can edit is something the other two tools in this post don’t do as well.
Two limits, stated plainly. First, the filing is still yours to do. Folders and tags only help if you put things in them, and most people don’t. Search across a few thousand unfiled notes gets you keyword matches, not an answer. Second, where the data lives: notes sync through iCloud under your Apple Account. They’re end-to-end encrypted only if you lock the note or turn on Advanced Data Protection, and some of the heavier Apple Intelligence work runs on Apple’s Private Cloud Compute servers rather than the phone. That’s a careful design, and it’s still a different promise than “never leaves the device.”
Obsidian: a workbench made of plain files
Obsidian stores your notes as a folder of plain Markdown files on your own disk. That single decision buys you the strongest ownership story in note-taking: if the company vanished tomorrow, your vault still opens in any text editor, in 2026 or 2046.
On top of the files sits the linking layer: [[connections]] between notes, backlinks, a graph view of how your thinking hangs together. Then plugins: thousands of community-built ones, all free, covering everything from spaced repetition to local AI. The app itself is free too, including mobile. The one thing Obsidian charges for that most people want is Sync, its end-to-end encrypted syncing service, at $4 a month billed annually ($5 monthly), though you can also sync a vault for free through iCloud or git if you don’t mind the setup.
Obsidian is the clear pick for long-form, connected knowledge work: research, a book, a codebase of ideas you’ll revisit for years. The trade is that it asks the most of you. You design the folder structure, choose the plugins, and maintain the system, and the system only pays off if you keep tending it. On the phone, capture takes noticeably more taps than Apple Notes; it’s a desktop-first tool with a capable mobile port, not a pocket-first tool. For people who enjoy building their own tools, that’s the fun part. For people who just want the thought out of their head, it’s homework.
Second Brain: capture without filing
Second Brain is our answer to a specific failure mode: you capture a lot and organize never. You dump a thought (typed, spoken, or shared from another app) and you’re done. An on-device model does the filing. Later you ask a question in plain words, and Ask answers from your own notes, citing the exact note each claim came from. When nothing you saved matches, it says so instead of inventing something. Notes with a date on them come back as reminders when they’re due.
The privacy model is the simplest of the three because there’s nothing to explain: no account, no server of ours, and sync is off unless you turn it on. An optional toggle mirrors notes to your own private iCloud, and nothing ever comes to us. The model that organizes and answers runs on the phone, so your notes are never sent anywhere to become useful. We wrote up how we keep a small on-device model from making things up in an earlier post; the short version is that citations and refusal are the product, not a disclaimer.
Now the costs, because they’re real. It needs iOS or iPadOS 26 and a device that can run an on-device model; Apple Intelligence devices use Apple’s built-in model, while other supported devices may need a one-time model download. There is no Mac or web app and no shared editing, so it is the wrong tool for a family list. It is also built for fragments, not manuscripts; if you are drafting 3,000 words, Obsidian is a better desk. Second Brain has no functional free plan. Eligible new subscribers may receive a 3-day trial, followed by $4.99 a month or $29.99 a year in the US. A subscription covers new notes, recordings, imports, and AI output; saved notes remain readable and searchable, recordings playable, and note and Ask text exportable after it ends.
The same six questions, side by side
| Apple Notes | Obsidian | Second Brain | |
|---|---|---|---|
| Capture friction | Very low: lock screen, share sheet, watch | Low on desktop; more taps on the phone | Very low: text, voice, share sheet, then stop |
| Organization model | You file: folders, subfolders, tags, Smart Folders | You build: links, backlinks, graph, your own structure | The app files: on-device model organizes each capture |
| Retrieval | Search (plain questions on Apple Intelligence phones), browse folders | Search, links, graph; more via plugins | Ask a question, get an answer cited to your notes; abstains when nothing matches |
| AI | Writing Tools, summaries; heavier tasks on Apple’s Private Cloud Compute servers | None built in; add your own via plugins, local if you want | On-device model organizes and answers; nothing leaves the device unless you turn on iCloud sync |
| Privacy / where data lives | Device + iCloud (Apple Account); end-to-end only with locked notes or Advanced Data Protection | Plain files on your own disk; optional Sync is end-to-end encrypted | On your device; no account; optional private iCloud sync (off by default) |
| Price | Free with the device | Free app and plugins; Sync $4/mo (annual) is optional | 3-day trial for eligible new subscribers, then $4.99/mo or $29.99/yr in the US; archive access remains available after lapse |
Pick by person, not by winner
If your notes are lists, scans, and things you share with family, use Apple Notes. It’s already there, it’s fast, and shared checklists alone justify it. Filing discipline optional but rewarded.
If you write long, think in connections, and want files you’ll still own in twenty years, use Obsidian. Accept that you’re adopting a hobby along with a tool; for the right person that’s the appeal.
If you capture constantly and know you’ll never file anything, and you have a supported iPhone or iPad, Second Brain is built for exactly you. Every thought goes in unfiled; the model organizes; Ask gets it back out with a citation you can check.
Most people should run two. We do: Apple Notes for the shared and the disposable, and our own app for the private stream of half-formed thoughts. If you want raw material to test any of these with, our journal prompts library is a free place to start. A week of daily prompts will show you very quickly whether you’re a filer, a gardener, or a dumper.