Last updated: May 23, 2026

Backdropia is a Chrome extension that draws a faint contour-line doodle behind AI chat sites (ChatGPT, Claude, Gemini, and others). This document explains what data the extension touches.

TL;DR

• Backdropia operates no server. We do not collect, store, sell, or share any of your data.
• Everything stays on your device — including any image you upload.
• The only outbound network requests go to Wikimedia Commons (commons.wikimedia.org and upload.wikimedia.org) to fetch public-domain source images for the automatic image pool.
• No telemetry, no analytics, no account, no cookies set by us.

What data Backdropia touches

On your device only

Backdropia uses Chrome's local extension storage (chrome.storage.local) to remember:

• Your preferences: on/off, mode (Ink or Color), and the Visibility level.
• A cached rendering of the current doodle (the edge map produced by the on-device pipeline).
• Up to three of your most recent image uploads — the JPEG you provided and the derived edge map — along with the currently active one.
• A short rolling history of the auto-pool source images recently picked, so the picker doesn't repeat itself immediately.

Backdropia stores data using Chrome's local extension storage on your device. Backdropia itself does not operate any synchronization service.

Uploaded images remain stored locally until they are replaced by newer uploads (the library keeps the three most recent) or you uninstall the extension.

Outbound network requests

Backdropia makes HTTPS requests only to:

• commons.wikimedia.org — the public Wikimedia Commons API (api.php). No API key, no account, no cookies, no identifying parameters. Used to refresh the rotating pool of public-domain source images approximately once per week.
• upload.wikimedia.org — the actual JPEG image files returned by the above API.