Is it worth it to go to both Sequoia National Park and Yosemite?

Yosemite is grander, and has Giant Sequoia's at one of the entrances to the park (Mariposa Grove) Oops, WARNING, Mariposa is closed for restoration right now. The other two redwood groves require light hiking. I'd still spend two days at Yosemite rather than trying to see Sequoia park on the same short trip.There is also a Coast Sequoia grove just outside of San Francisco (Muir Woods), easy to get to by car, and hugely impressive.

Yosemite is better, you have Yosemite valley and the rock formations and the waterfalls and Toluemme Meadows. In the south side of the park you have giant Sequoias at Wawona which are similar to the ones you will see in Sequoia. In Sequoia you have lots of groves of Sequoias plus the grandeur that is Kings Canyon in adjacent Kings Canyon national park. You will waste a few hours driving between the parks and both parks can't really be seen in a day so you would be better off just picking one and seeing the other some other time. I have been to both parks many times but never on the same trip.

It is worth seeing both, but not with the limited time you have. Go to Yosemite and save Sequoia for another trip

I have done both in one trip, but I have also given more time to each park. In an Ideal situation I would recommend a minimum of 4 days in Yosemite and 2 in Sequoia. You could be in Yosemite for a week(especially in the summer) and still not see all it has to offer.

Unless this is a once in a lifetime trip and you just must see Sequoia, I would say avoid it and spend more time in Yosemite.

If you must do Sequoia and Yosemite, you could actually go through Sequoia & Kings Canyon on the way to Yosemite. It is a VERY long day and you will miss a lot of sequoia but you can get the decent amount of sightseeing in. Leaving LA about 4AM would get you up in Sequoia by about 7-8AM. Give yourself about 6-8 hours to make it through the parks along the Generals Highway, and you are looking at about another 3-4 hours into Yosemite Valley.

Although, if you are going in the next week or so this is NOT an option due to a very big Wildfire that is affecting Kings Canyon and surrounding areas. This is also not usually an option in Winter due to snow conditions.

In Yosemite try to book a location in the Valley(Curry Village, Yosemite Lodge, or Awanahee Hotel(expensive)). As it takes anywhere from 1-2 hours to get into the valley from other areas.

That's a lot to do in 6 days, stick with Yosemite

If you had more time and would be camping or staying in the parks, both would be great. But if I had to choose 1, to visit, Yosemite would be it. There are many more things that you can get to easily and make a great 2 days.