What to Reply for Masha Allah?
There Is No One Right Response to Someone Who Says Mashallah to You. but If They Are Saying It an a Way to Share in Your Joy, Accomplishment, or Achievement...
There is no one right response to someone who says Mashallah to you. But if they are saying it an a way to share in your joy, accomplishment, or achievement then you can respond by saying Jazak Allahu Khayran which means “may Allah reward you”.
What should we reply for Alhamdulillah?
When any one of you sneezes and says 'alhamdulillah [praise be to Allah]', it becomes obligatory upon every Muslim who hears him to respond with: “Yarhamuk Allah [may Allah have mercy on you]'. Yawning is from the devil. When one of you feels like yawning, he should restrain it.”
What is the reply of Allah?
A more formal reply is "wa ʾantum fa-jazākumu-llāhu khayran" (وَأَنْتُمْ فَجَزَاكُمُ ٱللَّٰهُ خَيْرًا) which means "And you too, may Allah reward you with goodness".