Do I need a visa if I transit in Shenzhen?

Updated info: we don't want to explore the city, but I read that the airline company (Hainan) can provide a night in a hotel. But I don't know if the hotel is in the airport or not, I guess not but maybe there's something particular about it if it is a hotel provided by the company. Thank you

It doesn't matter where the hotel is, because all passengers will be subject to immigration inspection. As long as you arrive in Shenzhen by air, and you are in transit to a third country (but not Hong Kong or Macao), you will be eligible for 24 hours visa-free transit.

The free hotel by Hainan is not very good maybe a 1-2 star valued at around $15-20 euro? Also if flying in economy its shared with another person if flying alone. I'm guessing its offsite hotel. If you dont want to go into the city id suggest paying for the Hyatt which is attached to the airport near where the taxis are. its also just a few minute walk to the subway that takes you to the city.