Become a Dark Funnel Detective!

September 17 - September 24, 2018

We want to understand where Firefox downloads come from. So far, we know that 30% of Firefox installs come from the official Mozilla website or from known partners. The other 70% come from mystery download sources that we call “the dark funnel”. Some are friendly sites, but others put users at risk of getting old editions, a bad experience or even malicious installs. Help Firefox understand what’s in the dark funnel, by participating in this campaign and spreading the light!

RESULT: 1563 reports filled

“Understanding the dark funnel is one of Firefox’s most important goals this year. Every site reported by a community member gets us one step closer to our goal of understanding the entire dark funnel, which in turn helps us keep all Firefox users safe.”


Kirby Fowle – Senior Integrated Marketing Manager for Firefox

Participate in 3 easy steps:

STEP 1: Search the web

Use different combinations of keywords to find non-Mozilla sites that let users download Firefox without going first. Even if a site says “Mozilla”, it may still be part of the dark funnel.

STEP 2: Find “unofficial” Firefox Downloads

Investigate these websites to find “unofficial Firefox download” buttons (links that don’t redirect to or subdomains).

STEP 3: Report the website

Document those sites, how you found them, and what you found, using this form.

Throw a dark funnel event

You can gather with your local Mozillians and hold a dark funnel event in your city.

Just remember to keep your receipts, and look for a local Resources Rep that can submit a budget for you. You can expense up to 100 USD following these guidelines.