The Firefox Public Data Report is a weekly public report on the activity, behavior, and hardware configuration of Firefox users.

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All data is from a representative 10% sample from our Release, Beta, ESR, and Other channels for Firefox and the report runs once per week. Each datapoint covers a week’s worth of data (unless stated otherwise). All data is anonymized and aggregated to ensure user privacy. Mozilla publishes additional information about its privacy policy, its privacy principles, its data collection process, and its thoughts on internet privacy in general.

Source: Firefox Public Data Report