There are a number of free DNS that you can use:
- Google’s 8.8.8.8
- Quad9’s 9.9.9.9
- CloudFlare’s 1.1.1.1
- OpenDNS 208.67.222.222
- Norton 199.85.126.20
- CleanBrowsing 185.228.168.168
- Comodo DNS 8.26.56.26
Here is a good article comparing DNS for speed and features
For the speed results, The Top 5 DNS are:
Global Average Speed:
- CloudFlare: 4.98 ms
- Google: 16.44 ms
- Quad9: 18.25 ms
- CleanBrowsing: 19.14 ms
- Norton: 34.75 ms