There are many variables to that issue. Here is one tip to use.

These tests are not perfect. They test internet by sending ICMP*(Internet Control Message Protocol)  packets and thereafter calculating the round trip delay response.As ICMP works on layer 3 and Your application or say google works on layer 7. The higher layer counts ICMP packets as less priority and does not give accurate results.Kindly test by downloading and uploading the files from internet or ping to 8.8.8.8 along with http port number that is 80.

*ICMP (Internet Control Message Protocol) is an error-reporting protocol network devices like routers use to generate error messages to the source IP address when network problems prevent delivery of IP packets. ICMP creates and sends messages to the source IP address indicating that a gateway to the Internet that a router, service or host cannot be reached for packet delivery. Any IP network device has the capability to send, receive or process ICMP messages.