[hneel]

The headlights of my i30 don't work anymore.
First I checked one of the lightbulbes. At first sight it looked fine and I also checked it with a  multimeter.
Next I checked the fuse. This is the 15A "HEAD LAMP" fuse from the compartment behind the door. This one was fine too.

Then I googled and found that it might be a relay. However, I don't know which relay to check. I don't understand all those abbrieviations.
There are 2 boxes with relays and fuses in the motor compartment. I added some pictures:

[hneel]

Only the low beam lights are malfunctioning. The high beam is still working.

[Shambles]

[eye30]

The headlights of my i30 don't work anymore.
First I checked one of the lightbulbes. At first sight it looked fine and I also checked it with a  multimeter.
]

Have you checked the leads are all tight also swaped bulbs to check the seating in the holder is ok?

[nzenigma]

This lads on the money 

Many relays are interchangeable , so an easy way to check

[xiziz]

Are you sure its just not the bulbs?
All four sets of low beam bulbs ive gone through have blown at the same time on both sides, first time I was so sure it was the relay(after changing the fuses, that were fine) I drove home 400km in the dark with only fog and hi beams, lucky not a lot of oncoming traffic and dawn aproaching the last half illuminating some. They have also always blown when I start the car, now I always carry a spare set.

[nzenigma]

mate quite possible. I was just clarifying fuse and relay. Assumed OP had enough sense to check bulbs first.

Have made that assumption before, and found OP had not checked 
guess its me without enough sense 

[Shambles]

Are you sure its just not the bulbs?

First I checked one of the lightbulbes. At first sight it looked fine and I also checked it with a  multimeter.

[xiziz]

Ah, missed that