The task is about disabling zoom or pinch-to-zoom feature on mobile; especially for iframe. Googling for solutions always throws me with this HTML meta tag:

This may seems convincing at first, and it works; except for web developers worst enemy; Safari.

[Safari 10+ no longer respects user-scalable=no](https://stackoverflow.com/a/47866795) which brings another frustation. But the research never stops. This brings me to another solutions; via Javascript event listener.

The following code checks for touches. If it is more than 1 touches, disable default behavior(which most likely be pinch to zoom). Does it disable scrolling? No. Since scrolling only use 1 finger so it works normally. Solved! atleast for now....