I've tried rebooting the router but it does nothing. When things won't load on my phone my sisters phone works fine. Its just this phone.
Hmm, we could try some troubleshooting steps.
1.) Go to Setings>Networks>Wi-fi>Advanced Wifi
-Make sure "Internet unavailable" setting is unchecked under notifications then under "Useful Settings", try first to set "Keep Wi-fi on during sleep" to always, and leave unchecked "wifi signal weak" as well as "Allow Wi-fi scanning"
2.) You may want to change DNS settings of the phone
-Download a DNS changer app (set DNS, And DNS changer, Override DNS, etc). Next, try setting primary DNS to 8.8.8.8 and secondary DNS to 8.8.4.4 (Those are Google's public DNS)
3.) In terms of browser usage, you may want to observe on which browser (stock, or 3rd party such as chrome), does the issue occur more frequently. Then go to that browser's settings and do some re-configuration.
4.) If the problem is more evident when you connect to your home network, you may want to access your wireless router settings and change some settings such as the wifi channel, rts threshold, etc.
5.)By the way, what phone model are you using, and is it tied up with a carrier network?