How SFF Works
SFF helps you discover potentially relevant public profiles and web references by searching with a person's name or an online username.
Search results bring together links and references from different public sources so you can review the original pages yourself.
A search result is a possible lead, not confirmation of someone's identity or ownership of an account.
Start a search1. Choose how to search
Real Name
Search with a person's name to discover public pages and profiles that may be relevant.
- Quotation marks request phrase matching where supported.
- Without quotation marks, supported spelling variations and transliterations may be considered.
- Common names may return information about different people.
Username / Handle
Search with an online username to find potentially related public accounts.
- A leading @ is optional.
- Dots, underscores and hyphens are preserved.
- Usernames cannot contain spaces.
- For Mastodon, include the username and instance, for example @[email protected].
2. Choose the websites to search
Category filters let you narrow the websites included in your search. Available groups include social, professional, creative and technology, regional and other public sources.
You can also select an individual website where that option is available. Coverage and the type of information returned vary between websites.
3. Understand the result views
Discovered Results
Displays pages and references returned during the search. Open the original source to review its content and context.
Deep Search Links
Provides direct links to supported website search pages or profile routes. These links let you continue your research on the destination website.
A direct search link is not itself a confirmed profile match.
Expanded Web Search
When the initial results are limited, an additional expanded search may be available. It is an optional way to seek further public references.
4. Username result labels
When SFF checks a username on a supported website, the status describes what could be established from that particular check.
Matched
The website returned a response consistent with a profile being present. This does not confirm the account owner's identity or establish that the profile belongs to the person being searched for.
Not Found
The website explicitly indicated that the profile was not found. This describes the response at the time of the check. It does not prove that the username has never existed or cannot be found elsewhere.
Uncertain
The response did not provide enough information to determine whether the profile exists. It should not be interpreted as either a confirmed match or a confirmed absence.
Blocked / Rate-Limited
The website did not allow the check to be completed, or temporarily limited the request. This says nothing about whether the profile exists.
5. Search progress indicators
Primary search
Shows progress through the main search stage for your selected search.
Additional search
Appears when additional searches are carried out to broaden discovery where useful. It may not appear for every search. Its absence does not mean the primary search failed.
What does the percentage mean?
The percentage represents progress through the work being performed. It is not a measurement of how much of the internet has been searched and does not represent the probability that a result is correct.
Why might search coverage be incomplete?
Some websites may not respond, may restrict automated checks or may provide insufficient information. Available results can still be shown, but coverage may be incomplete.
6. Tips for more useful searches
- Include a middle name or another distinguishing name when appropriate.
- Try a known spelling variant when a name is commonly transliterated.
- Preserve punctuation in usernames.
- Include the full instance for Mastodon usernames.
- Review original pages rather than relying on titles, snippets or automated status labels alone.
- Compare independent context before deciding whether a result is relevant.
7. Limitations and responsible use
SFF searches public sources and presents potentially relevant information. It does not verify a person's legal identity, account ownership or relationships between different profiles.
Information can be outdated, incomplete or incorrectly associated with someone. Websites can change their pages, access rules and profile availability at any time.
Use SFF responsibly and respect people's privacy and the rules of the websites you visit. Do not use search results to harass, intimidate, stalk, expose private information or make decisions about someone without appropriate independent verification.
SFF is not a background-check, identity-verification or emergency service.
Please also read our Privacy & Cookies Policy and Child Safety Standards .
A little history
SFF began as a Firefox add-on approximately 15 years ago, designed to make multi-site profile discovery easier. It later evolved into an online service while retaining its original sffaddon.com address.