Best way to transform multiple digital signals from 12V to 3.3V
Figure 1. The ULN2003A can be driven by 12 V signals.

Note that the outputs are inverted and a pull-up resistor is required due to the open-collector output. Many programmable devices have programmable internal pull-up resistors saving external components.

Pay attention to Table 6.6 and the collector-emitter saturation voltage of around 1 to 1.6 V when low. This is a characteristic of the Darlington transistor arrangement.