Your data & backups
Your repertoire is your preparation. Chess Chunker keeps it — along with your marks, your review schedule and your endgame record — in your own browser, on your own device. There's no account, no user database, and no copy of any of it on my end.
Not as a promise — as a fact about how it's built. There's no database here to sell from. Nobody can buy what was never collected.
Your lines, your marks and your gaps never reach me. I couldn't study what you play, or feed it to anyone else, because I never have it.
There's no server holding your book, so there's nothing to break into, nothing to subpoena, and nothing to lose in somebody else's bad week.
The reason I can say all that is the same reason you have to look after it: you hold the only copy. No account means no password to lose, and also no way for me to restore anything. Those are one fact, not two.
So there's a button that writes the whole lot to a single file. It takes about ten seconds and it's the entire maintenance burden of owning this thing.
Same place — Settings → Your data → Backup → Load from file, then pick your backup.
It asks you to confirm, because restoring replaces what's in the browser rather than merging it. Two books can't both be right about when a position is next due, so the file wins and what's there now is discarded. If there's anything in the browser worth keeping, save a fresh backup first, then restore the old one.
That would be a nicer sentence than the true one, so here's the true one. Nothing of yours is stored anywhere but your device. But while you're training, the app does look positions up online — the endgame tablebase, and opening data for the position on the board.
Those are single questions about a chess position, the way a lookup in a book is. They aren't attached to a name or an account, because there isn't one. They aren't kept as a record of you. And what makes a repertoire yours — which lines you chose, what you marked, what you keep getting wrong, when you're next due — is never in any of them.
Because your opening preparation is competitive information. Most training sites hold every line you've ever studied, on their servers, tied to your name. That's usually fine and occasionally isn't — companies get sold, get breached, and change their minds about what they're allowed to do with what they hold.
Prep can't leak from somewhere it was never kept. That's the whole argument.
No. There's nothing to sign up for, no password, and no profile. If you bought this, I have a receipt — not a record of how you train.
None of these are dramatic events. They're ordinary things people do without thinking, which is exactly why the backup file exists.
Safari clears stored data for sites you haven't opened in a while. Adding Chess Chunker to your Home Screen stops that, and it makes it open full-screen with its own icon, like an app.
In Safari, press Share, scroll down, and choose Add to Home Screen. Do it on day one. It's the most useful thirty seconds you'll spend on setup.
Save a backup on one and load it on the other. It's a copy, not a sync — whichever you last restored is the current one, and work done on the other device afterwards won't find its way across. In practice: pick the device you train on, and treat the other as a visitor.
Then it's gone, and I'm sorry. I'd tell you if there were a copy on my end, but there isn't one to find — that's the other side of the trade at the top of this page.
Your courses and lessons come back on their own when you reopen it. What's lost is your own layer on top: your marks, your review dates, your records.
For the endgame trainer, yes — the opponent's replies come from a tablebase over the internet, which is how it always finds the toughest defence instead of a guess. Much of the rest keeps working without a connection.
After any session you'd be annoyed to repeat. Once a week is plenty for most people. It's one button and the file is small — there's no reason to be precious about it. Keep the last few.