Last updated: September 2026.

A flashcard app stores things by definition — your cards, your schedule, your lapse history. The question is where it stores them. FlashDeck’s answer is: on your device, in your browser, and nowhere else.

Your decks live in localStorage — here’s what that means

Every deck you create is written to your browser’s localStorage as a small JSON record under keys like flashdeck.v1.deck.<id>. localStorage is a per-site, per-browser, per-device store: the data is readable only by pages on this site’s origin, it persists across visits, and it is never transmitted to us — there is no endpoint that could receive it.

Practical consequences, stated plainly:

• We cannot read your decks. Not the card text, not your grades, not your schedule — they don’t exist on our side.
• You can inspect and erase them yourself. Your browser’s dev tools show every key; “clear site data” deletes all of it permanently. Export CSV from any deck’s Manage view if you want a copy first.
• Other people using this browser profile could see the decks in the same way they could see your open tabs — a shared-profile caveat, not a leak.
• Clearing site data, using private windows, or switching browsers/devices loses the decks. That’s the trade for zero accounts; the CSV page is the backup path.

What reaches our infrastructure

FlashDeck is static files served by Cloudflare. When your browser fetches a page, Cloudflare processes routine request metadata — IP address, user agent, timestamp, requested URL — to deliver the file and defend the site. We run no analytics beacons, no fingerprinting, no account system, and no server-side storage of study data. Grades and scheduling never leave the page that computes them.

Advertising

If ads are enabled on this site, third-party networks such as Google AdSense may set cookies or similar identifiers to serve and measure advertising, and — where permitted — to personalize it. You can disable personalized ads in Google’s Ads Settings or with a content blocker; the app behaves identically either way. Ad code cannot read your decks: it sees page context, not localStorage contents.

Questions and changes

Privacy questions: hello@tolerence.net or the contact page. If this policy changes, the updated text replaces this page with a new “last updated” date.