Google OAuth API provides a simple and powerful thanks to integrate the login system on the web site.
Google Login API permits the user to sign into web site|the web site} using their Google account while not sign on thereon website.
Google login system positively helps to extend the subscribers on your web site. as a result of these days most users have a Google account and that they will log in with their Google account while not registration on your web site.
If You Want to Login with google Account then Just Follow below Step:
1. Login With A google account like open gmail
2. Go to the Google API Console.
3.Click On new project
a. make your project name and click on create button wait for sec.
select your project if you have multiple project then enable api
4. then you see below image like webpage
5. click on library then search google+api
6.click on them and then enable it
7. create credentials
a. google+ Api
b. web browser
c. click on user data
and click on what credentials button
9. after click you saw a popup
now click on set up consent screen
then you will redirect to below image webpage
10. Type application name which you want and add Authorised domain name and just save them
11. create credentials
12. click on OAuth client ID and choose web Application
13. just see below image and follow them carefully
14. click on create button
15. after create you will see a popup where you see client Id And Client secret
16. click on credentials like below image
17. click on name (web client1 in my case)
18. download json file
19. put downloaded json file inside your google folder where you see client_credentials.json file replace all code of these file with your downloaded json code.
20. and download these Zip file