You can check-in directly from your home or office for most of the airlines.
Just follow this link: Web check-in.
Below is a list of airlines and their conditions for web check-in that allow passengers on-line registration for flights from Split Airport. For other airlines please try their web site.

You can register not earlier than 23 h and not later than 1 h before the flight of the following airlines:

You can register not earlier than 12 h and not later than 1 h before the flight of the following airlines:

You can register not earlier than 3 h and not later than 1 h before the flight of the following airlines: