Ypres is a lesser touristic spot in Belgium but with the same amount of history and importance like Gent or Bruge. It's easier to walk around and pass someone you already met. Therefore I think it's a safer city as there is also less nightlife.

Honestly, it's a small historical city where nothing too much happens. Nothing to be worried about. Of course it's better to walk with other people but in general no criminality there. I'm not worried about walking on the street during the night or day!

It is a smaller city in Belgium where it is pretty safe! I walk alone at night all the time and never felt really unsafe:) you usually won't see a lot of people on the streets at night. Around the station you can have weird drunk people but just avoid those.