Why do I need to know this

Directly translated, glad i deg is the same as jeg elsker deg. But be careful. The two aren’t often interchangeable.

What does it mean 

Glad i deg means “I love you”. It’s an expression you would use with your friends. Or your favourite colleague. Or the barista you meet every morning at your neighbourhood cafe. Glad i deg means I love you. But it can be thrown out there in more of a casual context. 

Jeg elsker deg also means, “I love you”. Which is why non-native speakers can quickly be under the wrong impression that they are interchangeable. Jeg elsker deg is typically used with someone you are in a romantic relationship with. If you told someone ‘jeg elsker deg’, it would mean that you are in love with them, which is a lot more serious than saying glad i deg. Glad i deg is expressing you have more of a lovely connection than a connection of love. 

Yes, in specific contexts the two can be interchangeable. You can tell your husband or wife glad i deg or jeg elsker deg. But you would never say jeg elsker deg to your favourite morning barista. Well, only if you have a major crush on them and want to reveal your feelings.

To be on the safe side, use glad i deg with everyone else other than that special someone in your life. 

Use it like this 

Tenk på alle som er glad i deg. – Think of all those who love you. 

Takk for at du tenkte på meg. Glad i deg. – Thanks for thinking of me. Love you.