Effective date: August 19, 2026

Fantrax Dynasty Tools is a local-first browser extension. It does not operate a developer-controlled backend, create user accounts, collect analytics, show advertising, or sell personal information.


When the extension runs on Fantrax, it reads the current league identifier and requests read-only league information, teams, rosters, standings, draft picks, draft results, and transaction history directly from Fantrax. The league identifier is sent only to Fantrax as required to make those requests.

The extension downloads public NFL statistics and player-identity data from GitHub-hosted nflverse releases. These requests do not include Fantrax league, team, roster, or player-selection information.

If the user explicitly enables FantasyCalc values, the extension sends only the derived value profile needed for the request—dynasty format, quarterback count, team count, and PPR setting—to FantasyCalc. It does not send the Fantrax league identifier, team names, rosters, or draft-pick ownership to FantasyCalc.

If the user imports an IDP CSV overlay, that file is parsed and stored locally. Its contents are not uploaded by the extension.

Like ordinary web requests, requests to Fantrax, FantasyCalc, GitHub, and their hosting infrastructure expose standard network information such as the user's IP address to those providers. Their handling of that information is governed by their own privacy policies.


League data, provider results, settings, and optional CSV values are stored in Firefox's local extension storage. The developer cannot access that storage. Users can delete this information by removing the extension or clearing its data through Firefox.

The extension does not read or store Fantrax cookies or credentials. For transaction history, the browser attaches the user's existing Fantrax session to a read-only Fantrax request in the same way it does for the native Transactions page. Diagnostic information remains local unless the user manually copies or exports it.


Fantrax Dynasty Tools is independent and is not affiliated with or endorsed by Fantrax, FantasyCalc, GitHub, or nflverse.

Privacy or security questions should be sent to the support contact identified in the extension's Mozilla Add-ons submission.