There are plenty of reasons for doing an online background check - and not all of them are dodgy. So here's how to do a thorough online background check without spending any cash.

I know what you're thinking - but hear me out. Plenty of reasons for doing an online background check exist, and not all of them are sketchy.

In fact, everyone should do at least one online background check on - you guessed it - themselves. After all, if you can find out sensitive information about yourself with a little (free) online sleuthing, there's no telling what employers, stalkers, and ex-girlfriends or -boyfriends will be able to uncover.

So here's how to do a thorough online background check without dropping any cash.

If you know your target's name

If you know name of the person you're looking for, the first places you should check are the usual venues - good old search engines and social networks. Google, Facebook, LinkedIn and Twitter are all good stepping-stones for discovering valuable information about people.

Google is your first stop for a DIY background check. Remember to use advanced search techniques when looking people up on Google or other search engines. Just enclosing your search terms in quotation marks will help immensely in weeding out non-correlated or irrelevant search results. If the person you're searching for has a common name, you should also add any information you know about them after the quotation marks. For example, if I search for "sarah jacobsson purewal" pcworld, I'm going to get more details about the Sarah Jacobsson Purewal who writes for PC Advisor's sister title PCWorld, helping to narrow my search down a bit.

Use any information you know about this person, including places of work, types of work, schools they've attended, cities they've lived in, and the names of other people they know. You can also use site-specific searches if you're looking for someone within a school or business. For example: site:pcworld.com "sarah jacobsson purewal" will give a list of search results found only in the PCWorld.com domain.

NEXT PAGE: Search social networks

  1. Not all reasons for background check are shady
  2. Search social networks
  3. If you don't know your target's name
  4. Web domain/IP address

There are plenty of reasons for doing an online background check - and not all of them are dodgy. So here's how to do a thorough online background check without spending any cash.

Searching your social networks

Social networks are fantastic sources of information - and it's all completely self-volunteered. This is why social networks are particularly handy for employers - because if it's on your Facebook page, it's not only information about you, it's information you've chosen to share with the world.

Facebook is indisputably the social networking standby - no surprise, as it boasts 500 million users. You can search for people by name and e-mail address, and modify the results by location, school, and workplace. If nothing shows up, they may have made their profile private and unsearchable.

If that's the case, you can do a site-specific Google search, and any public pages or groups they may have commented on will show up. For example, my personal Facebook profile is private and will not show up in Facebook search results, but if you type site:Facebook.com "Sarah Purewal" into Google, you'll see that I have commented on PCWorld's Facebook page. You can now see my profile picture, as Facebook doesn't allow users to make this private, even if you still can't search for me using Facebook's search.

Alternatively, you can use Openbook.org to search across Facebook's public pages (including status updates) for any search string you want and find search results listed with names, profile links, and pictures - perfect for your background check.

Other social networking sites, such as LinkedIn and Twitter, are also worth a look. LinkedIn usually reveals much less information about a user, because it's primarily a work-oriented social network. However, it is an excellent place to verify user's résumés and work histories (though, of course, a user can lie on his or her LinkedIn profile very easily).

Twitter is a different type of social network. Unlike Facebook and LinkedIn, Twitter asks for very little identifying information from their users. Thus, you'll often find people's Twitter accounts via their Facebook or LinkedIn pages - not necessarily by searching Twitter. Twitter can still give you a wealth of information, though it's more likely to give you an insight into their personality, interests, and style, rather than information you can use to find their address or phone number.

Find the Basics: phone number and address

Okay, so you've Googled your target and discovered all of their sordid beer-bong photos on Facebook, but what you really want is to be able to contact them. How can you get their phone number and address?

Look up phone numbers with 192.com. The site is a fairly accurate phone number lookup service. It offers a free way to look up people's phone numbers (you can narrow it down by county or town). BT also offers an online version of its Phonebook. However, it does not list numbers that are ex-directory .

NEXT PAGE: If you don't know your target's name

  1. Not all reasons for background check are shady
  2. Search social networks
  3. If you don't know your target's name
  4. Web domain/IP address

There are plenty of reasons for doing an online background check - and not all of them are dodgy. So here's how to do a thorough online background check without spending any cash.

If you don't know your target's name

Let's assume you want to search for someone whose name you don't know. Say you got a random phone call at 4am, or someone has been spamming you with a certain email and IP address combination, or you really want to find out who that jerk is on the forums you frequent, who goes by a particularly unusual handle.

Phone number/email address

While the US, a number of websites offer reverses telephone lookups – the ability to input a phone number and discover the name or the person or business it belongs to – these are rare in the UK. So it's inputting the number into a search engine and trawling the results.

One of the best places to do a reverse phone number lookup - and a reverse email lookup, while we're at it - is Facebook. While you can't look people up by phone numbers (even if they have it listed on their profile), you would be surprised at how many people leave their numbers on their friends' public walls. If you search for a phone number on Facebook and it's been left on someone's wall (or on one of those 'I lost my phone, need numbers' group walls), it will show up in the search results.

As for email, well, you can search for people on Facebook by email address. And even if their email address isn't publicly available on their profile, if it's in any way affiliated with their profile it will show up.

Username/handle

If you know nothing about the person you're trying to look up except for their username or online handle, fear not. So long as the username/handle is reasonably unusual, you'll be able to find a decent amount of information (which you can then use to perform other searches).

Search the 'Deep Web' with Pipl. Pipl is an aggregator that searches the parts of the internet that are often missed by regular search engines such as Google. Pipl allows you to search by name, email address, username or phone number. Pipl then crawls the web and aggregates all search results that contain your terms - so it's more of a one-stop shop for results.

Pipl is excellent for hunting down information about people whose name you do not know (as for people whose name you do know, it mostly just finds what you can find on Google and social networks). The username search is particularly useful, especially because a lot of people use one handle across the web.

Other aggregator sites also exist, such as ZoomInfo, which aggregates job and company information; iSearch and Wink. Unfortunately, aggregator sites can be as much of a pain as they are a convenience, as they often confuse people and spit back a mix of related and unrelated results.

NEXT PAGE: Web domain/IP address

  1. Not all reasons for background check are shady
  2. Search social networks
  3. If you don't know your target's name
  4. Web domain/IP address

There are plenty of reasons for doing an online background check - and not all of them are dodgy. So here's how to do a thorough online background check without spending any cash.

Web domain/IP address

If you want to find out who owns a domain, the process is pretty simple. The Whois database keeps a record of all domain registration data, and you can search it via a number of sites. Whois.net and Whois Source are just two sites that allow you to look up the registration data for any domain, and, if you're lucky, figure out who the owner is. Users are required to provide an address and a phone number when they register a domain. Of course, many website owners opt for private registration, which hides their personal information.

You can also look people up by IP address on Whois. You can use tools such as Geo IP Tool to search the Whois database and find out some info on the IP, specifically where the person is coming from. For example, my current IP is 207.239.54.194. If I enter this information into Geo IP Tool, I can see that I'm located in New York, New York, zip code 10019. Sure, that's not enough to be able to find out my phone number, but it's a start.

While Web domain and IP address lookups may seem like a dead end, they're often just the start of your search. If you can gather any information from the Whois database, you can use what little you know to aid you in your further searching. For example, if you're looking for me and you find out that I'm located in New York, thanks to my IP address, you can probably disregard the search results that put me in other places.

Well, there you have it, folks. Go forth and stalk yourself without spending a bundle.

See also: Analysis: How easy it is to commit ID fraud

  1. Not all reasons for background check are shady
  2. Search social networks
  3. If you don't know your target's name
  4. Web domain/IP address