The WhatsMyName project: the open dataset behind many username tools
By FreeUsername · Reviewed · Editorial policy
WhatsMyName is an open-source project, not a single app. It is a community-maintained file describing how to check hundreds of websites for a username. We are an independent tool that uses this data, so this page explains what the project is, who runs it, and how it differs from our checker.
Open username dataset. Project: github.com/WebBreacher/WhatsMyName · License: CC BY-SA 4.0
What is WhatsMyName?
Micah "WebBreacher" Hoffman created WhatsMyName in 2015 because the username checkers of the time produced too many false positives. Contributors around the world have since grown it into one of the most widely used username enumeration datasets in OSINT.
The core of the project is one JSON file, wmn-data.json. Each entry says which URL to request for a site, what a found response looks like and what a missing one looks like. Tools read the file and do the checking themselves, so anyone can build a checker on top of it. To be included, a site has to be publicly reachable and put the username in the profile URL.
The dataset is licensed under Creative Commons Attribution-ShareAlike 4.0. The project README points people who just want to search to whatsmyname.app, a free browser tool built on the dataset, and lists many other tools that use it, Blackbird among them.
FreeUsername is an independent tool. Our website and Android app use WhatsMyName data, credited under CC BY-SA 4.0, and our engine adds more sites we verify ourselves. We are not the project and are not run or endorsed by its maintainers.
Where our site list comes from, as of October 2026: the FreeUsername engine uses WhatsMyName data together with the Sherlock and Maigret lists, plus sites we add ourselves, re-checked nightly. The Android app uses the same open data, credited on its open-source page.
How to use WhatsMyName
- To search without installing anything, the project README recommends whatsmyname.app.
- To build your own checker, download wmn-data.json from the GitHub repository and read each site entry.
- To fix a false positive or add a site, follow the contribution notes in the repository; accuracy depends on reports from users.
- If you reuse the data, keep the attribution and share your changes under CC BY-SA 4.0.
WhatsMyName vs FreeUsername
| Feature | WhatsMyName | FreeUsername |
|---|---|---|
| What it is | A community dataset (wmn-data.json) plus a list of tools that use it | An independent web checker that uses this dataset in its own engine |
| Run by | Micah Hoffman and contributors | FreeUsername, unaffiliated with the project |
| Sites | Hundreds of carefully vetted sites | 3,450+ sites, on our own engine (WhatsMyName data plus sites we add) |
| License | CC BY-SA 4.0 | We use the dataset under CC BY-SA 4.0 and credit it |
| Web search | whatsmyname.app, built on the dataset | Nothing to install. It runs in the browser |
| Result states | Depends on the tool reading the data | Four statuses: found, not found, blocked, unknown |
| Domain check | Not part of the dataset | .com, .net, .org, .io, .us, .app and .dev through public RDAP |
| Export | Depends on the tool | JSON and CSV (no PDF) |
Based on WhatsMyName's own documentation as of 2026-10-13. Tools change; the project page is the final word.
Pros and cons of WhatsMyName
Pros
- Openly licensed data that any tool can use, so fixes help the whole community.
- Strict inclusion rules aimed at fewer false positives.
- Long-running project with an active contributor base.
- Its own web front end, whatsmyname.app, needs no install.
Cons
- Covers hundreds of sites, fewer than tools that merge several lists.
- Only sites with the username in the URL qualify, so some platforms cannot be included.
- It is a dataset first; how good the results are depends on the tool that reads it.
Who WhatsMyName is for
The project is for OSINT practitioners and tool builders who want a vetted, openly licensed list of username checks. If you want to search right now, use whatsmyname.app or another tool built on the data.
Try a username search in your browser
Free, no sign-up. Checks 3,450+ sites; the username is not stored or logged.
Frequently asked questions
Is FreeUsername part of the WhatsMyName project?
No. FreeUsername is an independent tool. Our website and Android app use the WhatsMyName data under CC BY-SA 4.0 and credit it, and our engine adds more sites we verify ourselves. We are not run or endorsed by the project or Micah Hoffman.
Who created WhatsMyName?
Micah "WebBreacher" Hoffman started it in 2015. It is maintained on GitHub with contributions from the OSINT community.
What license does the WhatsMyName data use?
Creative Commons Attribution-ShareAlike 4.0 International. You can reuse it with attribution, and adapted versions must be shared under the same license.
Can WhatsMyName search by email?
The dataset is built for usernames: every entry describes a profile URL with the username in it, so it does not look up email addresses. Our own email checker is coming soon. For now you can search the part of an address before the @, since many people reuse it as a username.
How is a WhatsMyName search different from yours?
whatsmyname.app checks the WhatsMyName sites. We check 3,450+ sites on our own engine, which uses the WhatsMyName data plus sites we add, and add domain checks and profile details. Both are free.
Related tools and guides
- Sherlock: Username search (CLI)
- Maigret: Username search (CLI and web UI)
- Blackbird: Username search (CLI)
- OSINT Framework: Directory of OSINT tools
- All OSINT tools compared
- OSINT username search · Reverse username lookup · Platform username checkers
- Username OSINT for beginners
Names and trademarks belong to their owners. FreeUsername is independent and not affiliated with or endorsed by WhatsMyName or its authors.