I am going on a backpacking/hiking trip and will be outdoors for about four days, would you recommend a water filter or a water purifier for this occasion? I am looking for the most comfortable and most convenient option for drinking clean water.

You can try the Sawyer Squeeze Water Filter System. It’s a 1 x 16 ounce soft bottle with a plastic syringe for cleaning, hydration system adapter, and a straw. You can drink directly from the Sawyer Squeeze but most people squeeze untreated water through it from a soft bottle to a clean container. The filter uses a hollow-fiber membrane filter that removes 99.99999% of all bacteria, such as salmonella, cholera and E.coli and removes 99.9999% of all protozoa, such as giardia and Cryptosporidium. The filter itself weighs 3 ounces. https://iwaterpurification.com/best-filtered-water-bottle/

I would say portable water filter bottles would be the best suited for you. Doulton TASTE bottle is a high performing filter that ensures you are alway drinking filtered water while travelling.

https://celticwatersolutions.ie/portable-filter-bottles/

It depends on where you are going (ie. the level of potential problems) and how much you want to 'purify'. Chlorine Dioxide tablets / drops work well for most bacteria/parasites etc. but, depending upon what you are needing to 'kill' can take anything from 5 minutes to 4 hours to work. When I went camping the first 2 times I took with me a water filter zero water, if you want to get it, read zero water reviews by the link.