It looks to me like the backsplash is not grouted. You can see all the way to the mesh behind the tiles. If that's the case, that is not good and those need to be grouted. Also, the counters appear to be a man-made type. Those do not need sealing. You should test out some counter safe cleaners to see if you can scrub that off, maybe a razor blade on an angle. Then clean the tiles really good and grout them.

Oh, and maybe it's just clear caulking along the counter and backsplash plane that has turned gross with stains?

Thank you! Do you have any recommendations on how to clean the tiles?

I think it’s clear caulking that has turned gross. I am going to try to scrape it off and reseal. In some areas it looks clear and then it turns brown? I bought the home from a contractor who lived there, so surprised they left it this way!

I agree with Amy, that looks like caulking. It needs to be cleaned off, and please be gentle when you clean the tiles, and get them grouted sooner rather than later. A bit of dawn dishsoap on a wrung out cloth, shud clean up the tiles. Dry them after cleaning, with a soft cloth, very carefully.

Thank you both! I am going to take a look at them again and maybe get a handyman to grout them. I bought the home from a contractor and he installed in 2015, so surprised if he didn’t grout them??

That is pretty shocking that he's left them ungrouted, and in a kitchen no less! Good luck with this little project. I'm sure it will turn out just fine.

That's a nasty caulk job. Dig it out with a credit card or a razor blade and replace with silicone caulk that matches the grout you'll use on the tile. Grout first, silicone last please.

Erin, I agree that the tiles need to be grouted, but make sure that they use silicon caulk at the change in planes, as Joseph said. It will need to expand and contract, and grout in that spot will eventually crumble. Do you have any extra tile? You might want to experiment with the grout because the tiles will look different (less luminous) when the channels are filled and no light can shine through the sides. That might be the reason the contractor didn't grout.