The Kia Venga came as first on the market and was a direct hit in 2010. While it took Hyundai at least one year more to release their ix20. The two hatchbacks with 5 doors are looking very similar, except the front. These cars are multiple purpose vehicles (MPV's), that's what's it make them ideal family cars.
Because you are sitting quite high in these cars you have more control of the traffic around you. Getting in the car is also more comfortable because of the higher placed seats. The compact dimensions make it easy to park, and some models are equipped with sensors that make park the car a peace of cake. Some people complain that the first Huyndai ix20 has less powerful engines installed in their models than KIA but Hyundai made now some new models with more powerful engines, even more powerful than those engines that KIA offers.
Room and boot capacity
The cars are very roomy inside and are performing very well with their boot capacity that can handle 440 liters, that's more than most MPV's (the Ford B-Max has 318 liters). The backseats are adjustable so you can ad extra space up to 570 liters. And if the backseats are folded down to a flat surface you can have 1486 liters of boot capacity.
Same parts for 2 different cars
From my own experience some parts of both cars can be used for each car, like the front-window that fits exactly in both cars. When I needed to repear the front window of my Hyundai ix20, because of a crack in the window, I needed a whole new front window. The carglass center did repair it with a Kia Venga window. What parts are more out there that can be used to assembly both cars?
Models and prices
The Huyndai brand made more style variations like the new ix20 Move and the ix20 Active. You have also more choice in the type of engines. But the engines of the KIA models are performing better. The Kia Venga and the Huyndai ix20 are having almost the exact same prices from 13000 (exclusive taxes) for the lounge versions to 18000 € (exclusive taxes) for the top versions.