Is it dangerous to leave this as it be?
This wall is located in the middle of the house and there are more smaller cracks around the house.

https://ibb.co/z4X5c7g

https://ibb.co/Vpthsp2

any rock blasting around there? maybe soil movement

park. Wanna know also

Repair the cracks and monitor. Then you will know which areas stop cracking. Is also for aesthetic purpose and 'peace' of mind.

My place was facing the same problem and spend almost 20k to strengthen the foundation. Most of the cracks stop except for minor recurrence in one area.

Holy sh*t!
Serious case ni....

No, it's not THAT serious.

Hairline cracks over doors and windows are likely due to settling. Houses of any age move and shift subtly over time, and the weakest area in a wall is the most likely to crack. ... Hairline cracks across walls and doorways do not indicate a structural problem; they should simply be re-taped and painted.

I used to have this problem in my previous house and I quickly sold it. Now I dunno the current owner is pissed off with his purchase or not....ehehehe

More pics below:
https://ibb.co/d6YHykB

https://ibb.co/M68xkcS

https://ibb.co/ZzcFrH0

I tried to dig out the cracked pieces of the wall and it is around 0.5cm thick, fortunately the inside of the wall has no crack.

Do I need a contractor to hack down the cracks and reapply the cement?

Any advise would be appreciated.

i think is plaster issue...

0.5cm is 5mm which is actually a serious case to concern about.

anyway, did you recently renovate your house? as i am aware, sea sand used for construction will have similar issue of minor cracks.

How old was the house? The crack happen recently? Buying from pemaju or build yourself?

The house is quite old, probably around 25 years ago when my parents bought it from the developer.
It was renovated around 5 years ago, before this it was just hairline cracks, recently only notice more cracks like in the attached images.

The renovation actually includes the extension of the front of the house and I actually noticed more hairline cracks appeared around the extension part.

On the other hand, I also noticed that I can smell the smoke coming from my neighbour even with all doors and windows closed, could it be related to the wall cracks too?

Is difficult to pinpoint the cause. The cheaper cost as I mentioned earlier is to redo the entire wall plastering and monitor from there.

the crack appears after 5 years? quite possible its land shift overtime, which is actually ordinary and will not post any harm to the structural integrity. you can re-plaster the wall and a new coat of paint would seal the crack.