Android app open-source credits

FreeUsername: Username Checker is built on open-source data. Thank you to everyone who maintains it. This app is not affiliated with or endorsed by any of the projects below. The full licence texts of the app's software packages also ship inside the app package.

Site data

The app checks usernames against site lists from three open-source projects. Each list is kept in its own file in the app, with its licence notice.

WhatsMyName

By Micah Hoffman (WebBreacher) and contributors. Source: github.com/WebBreacher/WhatsMyName. Licence: Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0).

Copyright (C) 2015-2026 Micah Hoffman. This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License.

The app uses an adapted copy of the WhatsMyName data (prepared for the app's on-device checker). That adapted data is shared under the same CC BY-SA 4.0 licence. The app's name refers to this dataset; the app is an independent project.

Sherlock

By the Sherlock Project. Source: github.com/sherlock-project/sherlock. Licence: MIT.

Site data derived from the Sherlock project. MIT License. Copyright (c) 2018 Sherlock Project.

Maigret

By Soxoj and contributors. Source: github.com/soxoj/maigret. Licence: MIT.

Site definitions derived from Maigret (https://github.com/soxoj/maigret), Copyright (c) 2020-2026 Soxoj. MIT License. Converted to the WhatsMyName record schema.

Username idea word lists

The "Find a free username" tool builds its ideas from these word lists. The app does this on your phone, so the name you type is never sent to us.

Friendly Words

By Glitch. Source: github.com/glitchdotcom/friendly-words. Licence: MIT.

Wordlists

By Ivan Malopinsky. Source: github.com/imsky/wordlists. Licence: MIT.

List of Dirty, Naughty, Obscene and Otherwise Bad Words

By Shutterstock and contributors. Source: github.com/LDNOOBW. Licence: CC BY 4.0. We use it only to keep rude words out of suggestions.

Fonts

Inter, IBM Plex Sans Arabic, Mukta and JetBrains Mono, all under the SIL Open Font License 1.1. The licence texts ship with the app.

Website icons

Logos for the most popular platforms ship inside the app. Others are loaded from DuckDuckGo's and Google's public favicon services. Logos and names belong to their owners and do not imply endorsement.

Questions

If you maintain one of these projects and something here is wrong, tell us in the app: Settings → Send feedback.