Privacy
Last updated October 13, 2026.
The short version
League Lens has no accounts, no ads and no tracking cookies. It reads public fantasy league data (and, only if you opt in, your private ESPN league) to show you analysis. We don't sell or share anything.
What runs in your browser
Almost everything. League data comes straight from Sleeper's and ESPN's public APIs into your browser. Things like your Sleeper username, recent leagues and which team is yours are saved in your browser's local storage, on your device only, so the site can remember them. Clearing your browser data removes them.
What we store on our server
Only: (1) anonymous daily usage counts, such as how many times a tab was opened that day, with no IP addresses, user IDs or cookies; (2) the message and optional contact you type into the feedback form, if you send one; (3) if you turn on weekly reminders, your browser's anonymous push address (no name, username or league), deleted when you turn reminders off; (4) if you use the Discord bot, which Discord channel is linked to which league ID.
Private ESPN leagues
If you choose to connect your ESPN login (via the bookmark, manual option or the League Lens for ESPN browser extension), your two ESPN login cookies (espn_s2 and SWID) are saved in your browser only. Each time the site needs data from your private league, they're sent with that request to fflens.app/api/espn, which forwards one read-only request to ESPN's fantasy API and returns the result. They are never logged or stored on our server. Disconnect anytime with the Disconnect link on any ESPN league page, or by logging out of ESPN.
The League Lens for ESPN extension
The extension only runs on fantasy.espn.com football pages. When you click its button, it reads your espn_s2 and SWID cookies and opens your league on fflens.app with them in the address fragment, which browsers never send to any server; the site saves them in your browser and removes them from the address bar immediately. The extension collects nothing else and sends nothing anywhere else.
Analytics
We use Cloudflare Web Analytics, which counts page views without cookies or fingerprinting.
Third parties
Your browser loads data from Sleeper, ESPN, FantasyCalc and DynastyProcess (via GitHub) to build the analysis. Their own privacy policies apply to those requests.
Questions
Use the feedback form at fflens.app/#/feedback.