Last Updated: September 21, 2026
GerrymanderX ("the App") is a precinct-level election atlas for macOS developed by Chen Yue. It lets you download public U.S. election result databases, explore them on a map, compare elections, and draw your own groupings of precincts. This policy explains what data the App handles and — more importantly — what it does not. The short version: signing in is optional; if you do sign in, the App learns who you are and nothing else about you is collected; everything you download or create stays on your Mac.
An account is optional. Every feature of the App is available after choosing Continue without signing in on the first screen, and in that case the App collects no personal data at all. If you prefer an account, you create one by signing in with your Apple ID (Sign in with Apple) or with your Google account — there is no separate registration form and no password held by us. Sign-in is handled by Firebase Authentication, a service provided by Google LLC, acting as our processor.
When you sign in, we receive from Apple or Google and store the following about you:
That is the entire account record. We use it only to let you into the App and to show you which account you are signed in as. It is not used for advertising or profiling, it is never sold or shared, and we do not receive your Apple ID or Google password or any other content of those accounts.
Your signed-in session is kept in the macOS Keychain on your Mac so you do not have to sign in every time. Signing out removes it.
Beyond the account record described in Section 2, nothing. The App collects no usage analytics, no crash reports, no location data and no advertising identifiers, and it contains no advertising or third-party tracking SDKs. Nothing you do inside the App — which elections you open, which regions you inspect, which layers you draw — is recorded or transmitted to us.
The App makes network requests in exactly three situations:
The data downloads and update checks are plain file requests. They carry no account, identifier or user-generated data; the hosting provider sees only the standard network metadata any download discloses (such as your IP address and the requested file). Apart from signing in, nothing is ever uploaded from the App.
The App stores the following, entirely on your Mac, inside its sandbox container at ~/Library/Containers/com.chenyue.gerrymanderx/Data/Documents/GerrymanderX/:
None of this is linked to your account. Your custom layers and downloads belong to the Mac they were made on: they are not uploaded, not synchronised between devices, and not attached to your identity. Signing in on a different Mac will not bring them with you, and signing in as a different person on the same Mac shows the same locally stored data.
You can delete any downloaded election or custom layer from within the App; deleting an election also deletes the custom layers that depend on it. Removing the ~/Library/Containers/com.chenyue.gerrymanderx/Data/Documents/GerrymanderX/ folder removes everything the App has stored on your device.
Your account record is kept until you delete it. You can delete it at any time from within the App, under Settings → Account → Delete Account. This permanently removes your name, email address (or relay address), profile picture and user identifier from Firebase Authentication; it cannot be undone. If you signed in with Apple, you can additionally stop sharing your Apple ID with the App under Sign in with Apple in your Apple Account settings. You may also write to us at the address in Section 12 and we will delete it for you.
Deleting your account does not touch the data on your Mac, because that data was never connected to the account. Remove it separately as described in Section 5.
The election data the App offers for download is compiled from the following public sources, used under the terms of their respective licenses:
Changes made: the data has been reformatted, merged across sources and elections, and in places modified. Missing precinct outlines were added from state and county GIS layers; for years without precinct data, counties are used as reporting units and split along congressional-district lines for U.S. House races. Any errors introduced in this process are ours, not the original publishers'.
GerrymanderX is not affiliated with, sponsored by or endorsed by any of the organizations or authors named above.
This data describes aggregate election results by geographic area and contains no information about individual voters.
The App may open this policy in your browser, and the Feedback action opens your email client with our support address and the App version pre-filled — nothing is sent until you send it yourself. Those sites and apps are governed by their own policies.
Signing in relies on Firebase Authentication and Google Sign-In, both provided by Google LLC, and on Sign in with Apple, provided by Apple Inc.; their handling of the data described in Section 2 is governed by the Google Privacy Policy, the Firebase Privacy and Security information and the Apple Privacy Policy. Apart from these, the App is built with open-source software (Flutter and SQLite, among others), which runs locally and transmits nothing.
The App is not directed at children. Signing in, which is optional, requires an Apple ID or a Google account, each subject to its provider's own minimum age requirements. We collect no data from children beyond the account record any signed-in user provides.
If the App's behavior ever changes in a way that affects privacy, this policy will be updated and the "Last Updated" date revised before the change ships.
Questions about this policy, or requests to delete your account: support@gerrymanderx.com