Option A
Markdown files
The ownership gold standard — plain files you control, forever. But raw text is austere: hard to read without yet another renderer, images live by reference, and rich layout simply doesn't fit.
local-first · block-based · plain .html files
A second brain you actually own.
CuO Notes is a block editor that writes every note as a clean, browser-readable .html file. Text stays in the file; media lives beside it in a plainly named assets folder. As pleasant as Notion. As portable as the web. As yours as paper.
No account needed · works offline · your writing stays local
why CuO exists
Every notes app makes you choose. You shouldn't have to.
For years, a second brain meant picking your compromise: own your files, or enjoy writing in them.
Option B
Hosted notes apps
Often wonderful to write in. But the working copy usually lives in a company database or ecosystem, so long-term access depends on accounts, exports and product decisions.
The overlooked answer
HTML
The web's native document format. Modern devices already have a reader — the browser. HTML handles rich text, images and tables, is understood by automation tools, and does not depend on one notes app to remain readable. It just needed a calmer editor.
CuO Notes is that editor. Blocks in front of you, plain .html files behind you. Delete the app tomorrow — every note still opens.
see it move
Watch it work.
Four live scenes show the writing experience, focus mode, file portability, and how open files can work with the tools you choose.
demo 01 — quick switcher
Everything is one keystroke away.
Press ⌘K anywhere. Type three letters. You're on the page you meant — pages, sections and search live in one calm list that never makes you think about where things are filed.
demo 02 — focus mode
Flip a switch. The room goes quiet.
Focus mode clears the sidebar and the toolbar, narrows the page, and leaves you alone with the words. Everything comes back the moment you ask for it.
open it without CuO
The note still works without the app.
Open any note in place and it renders in a browser with its styling intact. If the note has media, its plainly named .assets folder stays beside it. No conversion, account, or export step is required.
demo 04 — bring your AI
Every AI already speaks your format.
Your notes aren't trapped behind an app or an API. They're plain files in the web's own language — so any AI agent, from Claude to a local model, can read, edit, tag and reorganize your knowledge base right in the folder. Your second brain gets a staff.
what's inside
A full block editor. A plain folder underneath.
Write in blocks
Headings, lists, to-dos, toggles, quotes, callouts, dividers, code — press / and build the page you mean.
Storage you control
Chrome and Edge can use a folder you choose. Other browsers keep notes in private local storage with one-click ZIP backups.
Browser-readable pages
Each note is a clean .html file with its styling included. Media stays beside it in a predictable assets folder.
Images & tables that behave
Paste images with captions, alt text, alignment and sizing. Real tables with header rows. All of it lands in the file.
Find everything
Full-text search, #tags, backlinks between pages, and a ⌘K quick switcher that gets out of the way.
Calm by design
Instant autosave, a focus mode that quiets the room, light and dark themes, adjustable width and type size.
Private by default
An installable app that works fully offline. Notes never touch a server — an optional account syncs preferences, never your writing.
Export that means it
One click turns your workspace into a deployable static site, or a .zip backup. Native Mac & iOS apps are on the way.
And the palette keeps growing — even more block types are on the way, and every one of them saves as the same plain .html.
coming soon
pricing
Free to think in. Fair to live in.
A block is a paragraph, a heading, a list item. Limits only ever apply to creating new blocks — reading, editing and deleting are never locked.
Just visiting
$0 no account
- Every feature, no sign-up
- Up to 100 blocks
- Your files stay yours, always
Free account
$0 forever
- Up to 1,000 blocks
- Preferences & favorites synced across devices
- Notes still never leave your device
Unlimited is in development. Lifetime and subscription options are planned, but pricing has not been announced. We would rather be clear than put a placeholder price here.
Whatever the tier, the promise is identical: your notes are plain files in your folder. Downgrading, cancelling, or walking away never takes a single word from you.
questions
The honest answers.
Where are my notes stored?
In Chrome and Edge, they live in a folder you choose as ordinary .html files with media folders beside them. Safari and Firefox use private browser storage with ZIP backup. Your writing is not uploaded; an optional account syncs preferences such as theme and favorites.
What happens if CuO disappears tomorrow?
Your text remains in browser-readable HTML files. Keep a note beside its assets folder and a modern browser can open it without CuO. That direct readability is the point of the format.
Which browsers work best?
Chrome and Edge support the full experience — a real folder of your choosing, via the File System Access API. Safari and Firefox work too, using private in-browser storage with one-click .zip backups. Native macOS and iOS apps are in development.
Does it import or export Markdown?
No — and deliberately. CuO doesn't need an exit format because the working format is already the portable one. If you want to publish, the static-site export turns your whole workspace into a deployable website in one click.
Is there sync between devices?
Your notes are files, so they sync with whatever you already trust — iCloud Drive, Dropbox, Syncthing, a git repo. Point CuO at the synced folder on each machine. Built-in preference sync ships today; richer options are on the roadmap.
Start a local workspace.
No sign-up or download. Choose a folder in Chrome or Edge, or start in private browser storage elsewhere. Your writing stays on your device.
Open CuO Notes