If you have a phone number that needs to be investigated, here are 7 free open-source (OSINT) tools that can provide assistance.
- Search Engines
The first method is to search through the numerous search engines available. Inputting the phone number will return different results. The key to using general search engines is to try different variations. This can be a tedious process, with the classic "no results" screen appearing multiple times. As with any OSINT investigation, persistence is key, and remember to take notes to avoid doubling your workload. Here are some examples to remember for the US and UK formats:
US format:
2124567890
212-456-7890
(212)456-7890
(212)-456-7890
212.456.7890
212 456 7890
+12124567890
+12124567890
+1 212.456.7890
+212-456-7890
1-212-456-7890
UK format:
02071234567
020 7123 4567
020-7123-4567
(+44)02071234567
(+44)020 7123 4567
+4420 7123 4567
004420 7123 4567
+44 (0) 20 7123 4567
+44(0)2071234567
Sometimes, companies attach additional information to phone numbers. If you're lucky, you may be able to obtain names, email addresses, and addresses.
- NumLookup
Link: www.numlookup.com
After exhausting search engines, you can turn to specific phone number search engines like NumLookup. Simply search a number, and the tool will retrieve owner names, addresses, social media profiles, and other data. While some results may require logging in to access, no account is needed. The website claims to be the number one phone search tool for US numbers, but they also provide searches for Australia, Canada, France, Germany, Italy, India, the Netherlands, New Zealand, Singapore, Spain, and the UK. I recommend searching your own number on all these tools. Personally, I discovered public information that I didn't want to share and was able to opt out. Simply visit the following link and fill out the required fields for the opt-out request: www.numlookup.com/opt_out
- Epios
Link: www.epieos.com
If you have an email account, this is a good web search tool. It has a new feature for searching phone numbers. Similar to the above, simply input the target phone number, and the tool will search the internet for account details from services like Google and Skype.
- Truecaller
Link: www.truecaller.com
Another popular tool is Truecaller. For this website, you need an account, which also records a significant amount of your own data, such as name, email address, search information, and IP address. Therefore, having a browser that is as private as possible is a good idea (I will post an article about the best free private browsers and their settings in the near future).
- Spydialer
Link: www.spydialer.com
Similar to the options above, this is just an input and search tool. However, it is limited to the US. The service also offers options to search for individuals, addresses, email, and business details. I personally haven't used it as I live outside the US.
- Who-Called
Link: www.who-called.com
Who-called is a service where investigators can see if previous victims of malicious callers have reported anything related to the target phone number. Its mission is to "identify, report, and block unwanted calls from malicious callers," which helps to carefully examine whether a call is legitimate. If you receive a suspicious call from a certain number, you can add notes to that phone number. The service also provides coverage for 38 different countries/regions, which is better than most of the previous options on the list. Each country/region has similar services, such as tellows.co.uk for the UK.
- Cocofinder
Link: www.cocofinder.com
This is another completely free service that I recommend as a source to cross-check the results from the aforementioned tools. I say this because although the service is "completely free," there are multiple pop-up windows to carefully navigate before obtaining results.