Many people use Google (IP = 8.8.8.8).  There are other free DNS services that do better than Google, but none that I have found that do better than this one:

https://cleanbrowsing.org/filters

I recommend using "Adult filter" more than "Family filter".  Youtube in Safe mode doesn't let you comment on videos.  It blocks worship videos and allows LGBT propaganda.  Google is in the left pocket.  Still, if there's a problem, blocking more is probably better than blocking less.

To get the IP on your phone changed, consult the manuals here or call your mobile phone tech support people.  Be sure not to use the open DNS IP, because clean browsing is much better.  The process is the same, the IP is not.  The way I changed my phone DNS was through the T-mobile website.  I don't know how I found it, so you're on  your own there. 

To get the IP on your router changed, follow these steps.
Steps 1 & 2
Start -> cmd.exe



Step 3
Type this at the command prompt:
ipconfig

Step 4
Find the "default gateway" - usually starts with a 192.168.x.x (where x is a random number)



Step 5
Highlight all 4 numbers of the gateway with all three dots (Ctrl+M, or right click the text and then "mark"; pressing enter copies it). 
(The "gateway" IP is a local network IP.  It is only true inside your house.  The clean browsing IP is a global IP.  It is true anywhere in the world.  Same standard, different scope.)

Take your gateway IP to a web browser (i.e. Google Chrome, Firefox, Microsoft Edge), paste it in the location bar (Alt+D, Ctrl+V).  If pasting didn't work, find your command prompt and manually type the IP into the address bar.  Don't forget the dots.  If you enter and nothing happens after 20 seconds, try typing this instead:
http://192.168.x.x
or
https://192.168.x.x

Do not type x.  Those are substitutes for the actual IP address numbers you got from the command prompt where it says "default gateway".

Step 6
This step may be hard, it may be easy.  You need to log into your router.  Most routers have a default login.  If you look at the actual box, you will see the brand name, be it cisco, or netgear, or TP-link, or Linksys.  Once you have the name / model of the router, you have to do a quick search for default login.  Here's an example:
https://swisscows.com/web?query=linksys%20router%20default%20login&region=en-US

If the default logins don't work, your ISP probably has the login.  You will need to call them to get instructions on how to log in.

Step 7
In the router settings, you will need to find somewhere the default DNS settings.  It is usually in the same place as your ISP login settings.  It may have a "default" DNS to your ISP.  Change it to the IP you found on the Cleanbrowsing site.  After changing the default DNS,  you will usually have to reboot the router.  There's a reboot option in the settings, or you can unplug the router and plug it in again after 10 seconds.  Be sure you "save settings" before you reboot.

Step 8
A good way to test if it works is to change the DNS to the super strict one first.  Then use Youtube.  If the comment section of all videos is turned off for restricted mode, the DNS change was successful.  You will not likely be able to play the live 268 streams on that setting.  Then you can go back and change it to the adult filter DNS and let it stay on that one.

If you want to test the actual porn blocking, do it with your wife, your mom, your sister.  You can turn off images before you go searching that stuff.  Instructions on the page that brought you to this one.  That's all I need to say about that.