There are times where you missed a call or a number has been disturbing you all along but you don't know who owns the number. There are websites and applications you could use to get the details of those numbers. The websites and applications use a process called reverse phone look up. This reverse method is exactly opposite to the regular lookup where you try to find the phone number of a person using his/her name.
Free reverse phone lookup service helps us to identify the name and other details of a person like his location through his sim card registered area. This service looks up for a given number in different databases which is located all over the world to find the caller id and other details. Listed below are some of the applications and websites you could use
1. TrueCaller
This website will help you to trace the name and the location of an unknown number. It can be used on the website and on major mobile operating systems like Android, Blackberry and iOS. Good thing it is also free.

2. Trace Phone Number
 This website is an Indian based website which help you to get the details of an unknown number. This site traces Landline, mobile, STD or ISD numbers. For landline or STD, you will also get to know the operator information also. This tool cannot provide real-time details like the exact location of a number.

3. Mobile Tracker
 This website gives you the geographical information of a number like longitude and latitude, service provider, signal etc of a phone number. Just input the number in the search button and press enter. If the number is in their database, it would bring out all the information concerning that number.

4. TrueDialer
 Truedialer makes your phone smarter by enriching past calls with names and photos, and operates faster by identifying phone numbers while you dial. It also helps you avoid unwanted calls from wrong numbers. You can get it on Android and Windows

 So the above websites and applications will help you to track those unknown numbers that you receive in your mobile. Sometimes you can’t trace some particular number because of its absence in the database of that site. So try another site to lookup for the details. You probably may find it.

Good luck!!!