Keeping Notes in Your Browser: What the Notepad Saves, and What It Can Lose

The online notepad is one of the few pages on this site that remembers anything. That makes it useful, and it makes its storage rules worth reading before you trust it with something you cannot retype.

Where your note actually lives

Nothing is uploaded. The text is written into your browser's localStorage under this site's own address, in a record named notepad_content. Practical consequences:

• It survives reloads, restarts and closing the tab. There is no session expiry.
• It does not survive clearing this site's data — which a browsing-history wipe also does, if "cookies and other site data" is included in it — and it does not exist at all in a private/incognito window once you close it.
• It is per browser, per device, per address. Two tabs of Chrome on one machine share it; Chrome and Edge do not; your phone does not. Because the storage is keyed by the site address, arriving through a preview address instead of aitoolmao.com gives you a separate, empty note rather than the one you wrote.
• There is no sync, no account, and no history. One note, current version only.

Font size and the line-number switch are stored the same way, as separate records, so those preferences follow the same rules as the text.

Auto-save is debounced by 300 milliseconds

Every keystroke schedules a save, and the save happens 300 ms after you stop typing rather than on each character. That is what keeps the page comfortable, and it is also the only window in which work can be lost: if you type and close the tab within about a third of a second, that tail of typing is gone. There is no save-on-close handler. Press Ctrl+S before switching away if the last characters matter.

The status line at the right of the bar reads Last saved: HH:MM:SS and reflects the most recent successful write. Two quirks about it:

• Loading the page with an existing note re-saves that content immediately, so you can arrive at a page already showing a fresh timestamp you did not cause.
• If the write fails — the usual cause being that this site's storage quota has filled up, which browsers cap at a few megabytes — the failure is swallowed silently and the label keeps showing the previous successful time. A stale Last saved is not a promise.

Two tabs will overwrite each other

The page does not watch for changes from other tabs. Open the notepad twice, write in both, and the tab that saves last wins the stored content; the other tab keeps showing what it has in memory and will happily overwrite on its next save. Keep it to one tab, or export with Download .txt before switching.

The counters on the status bar are not the ones on Text Statistics

Three numbers along the bottom:

• Characters counts UTF-16 code units, so an emoji counts as 2. Word and character counting explains where this site's measurements diverge.
• Characters (no spaces) excludes spaces, tabs and both line-ending characters.
• Chinese Characters counts Han characters specifically, which is the reliable one for a note written mostly in Chinese.
• Words counts English words only, matched as runs of ASCII letters. A note written entirely in Chinese reports 0 Words — that is the rule, not a failure to load.
• Lines counts by splitting on \n. A note that ends with a newline reports one more line than you can see, and an empty note reports 1, not 0.

Formatting, export, and the two buttons that surprise people

This is a plain-text editor. No bold, no headings, no images, no markdown rendering, no find-and-replace. What it does have:

• Font size — Small (12px), Medium (14px), Large (18px). Default Medium.
• Line numbers — a gutter down the left. It is a separate column with its own fixed type metrics (13px), while the text column changes size with the font setting. So the numbers line up with the first line and then drift progressively as you go down the note — larger font, faster drift. Cosmetic, but if you are counting on the gutter to locate a line in a long paste, read the number as approximate.
• Download .txt — a UTF-8 file named Notepad_YYYYMMDD.txt. The name contains a date and nothing else, so two downloads on the same day get the same filename and your browser silently appends "(1)" to the second. The file is written without a byte-order mark; if you open it in an older Windows spreadsheet application expecting Chinese, it may guess a legacy code page and show garbled text — use Import with the encoding specified, or a plain text editor.
• Copy All — uses the clipboard API, falling back to a legacy selection copy. In the fallback path the confirmation alert fires whether or not the copy succeeded, so verify by pasting.
• Insert Timestamp — writes YYYY-MM-DD HH:MM:SS in your machine's local time. It replaces any text you have selected rather than inserting around it; with nothing selected it lands at the cursor.
• Ctrl+S — saves immediately instead of waiting for the debounce. It is bound to Ctrl specifically, so Cmd+S on a Mac does nothing, and the editor must have focus for the shortcut to fire.

Clear does ask for confirmation, and it persists the empty note straight away — so there is no "undo" and no earlier version to get back.

Is it private?

Your text never leaves the machine as part of the app's behaviour: no request carries the note's content, no account is involved, and there is nothing to sign. The page itself loads the same third-party scripts as the rest of the site — analytics, the Live2D widget on desktop, advertising. If a note contains anything you would not want associated with a page that carries analytics, keep it somewhere whose page has neither: this is a convenience pad, not a vault.

For anything you cannot afford to lose, use Download .txt — a file on your disk obeys your backup routine, and localStorage does not.