Every other online notepad uploads what you type to a server. This one does not. Your documents are stored by your own browser, autosaved as you type, and still there when you come back, even after you close the tab. Nothing is transmitted anywhere, so there is no account to create and nothing to delete later.
Most online text tools send whatever you paste to a server, run the work there, and send a result back. Your words sit in someone else's logs, backups and databases, and you have to trust a privacy policy.
Local-first means the opposite: the whole tool is downloaded to your browser and runs on your own device. Nothing you type is transmitted anywhere: not to us, not to anyone. There is no server that could receive it, which is a stronger guarantee than a promise not to look.
Three consequences worth knowing:
You do not have to take that on trust. Open your browser's developer tools, watch the network panel, and type: nothing appears in it.The network's verify page walks through the same check on every Jamuny tool.
Documents are stored in IndexedDB, a database built into your browser, on this device only. That is what makes the editor work offline and what makes it private: there is no server holding a copy, so there is no account to create, no privacy policy that matters, and nothing to delete later.
The trade-off is worth stating plainly. Because storage is per-browser and per-device, notes written here will not appear on your phone, and clearing site data in your browser settings removes them permanently. If a document matters, export it. The editor is a scratchpad you can trust with a password reset code, not a sync service.
Multiple documents in tabs, each independently named and renamed. Find and replace with regular expressions, whole-word matching, and the option to restrict a replacement to just the text you have selected. Column selection by holding Alt while dragging, which is the feature people miss most when they move off Notepad++.
It also reads and writes real files. In Chromium browsers the File System Access API lets Save overwrite the file you opened, so the editor behaves like a desktop application rather than a download machine. Firefox and Safari have not shipped that API, so there opening uploads a copy and saving downloads one.
Paste JSON, JavaScript, Python, CSS, HTML, XML or Markdown and the editor recognises it from the content and colours it accordingly. Detection is deliberately conservative: it demands structural evidence rather than a single suggestive word, because colouring a shopping list as code is worse than leaving it plain.
If it guesses wrong, the language picker in the status bar overrides it, and your choice sticks to that document rather than resetting on the next keystroke.
In your browser's IndexedDB storage, on this device only. They are never uploaded. Clearing your browser data for this site deletes them permanently, so export anything you need to keep.
Yes. Edits autosave roughly half a second after you stop typing, and every document reopens automatically on your next visit. The one thing that removes them is clearing site data in your browser settings.
In Chrome and Edge you can open a file and save changes straight back to it. Firefox and Safari do not support that browser API, so there you open by uploading a copy and save by downloading one.
Comfortably up to about 20 MB. Past that the editor warns you, and it refuses files over 50 MB: a browser tab cannot hold a file that size without freezing.