Expresses a strong level of happiness, more than just 'happy' or 'pleased'. She was high as a kite after her performance received a standing ovation.
Pro Tip 2/3
Emotive Imagery
The phrase creates a vivid mental image of someone floating with joy, like a kite flying high. Winning the award, he felt as high as a kite, nearly floating with joy.
Pro Tip 3/3
Colloquial Use
Used in informal situations among friends or family, but not in formal contexts. I've never felt so high as a kite, this is the best day of my life!