[Verse 1]
[Liam]
You're insecure,
Don't know what for,
You're turning heads when tu walk through the door,
Don't need make-up,
To cover up,
Being the way that tu are is enough,

[Bridge]
[Harry]
Everyone else in the room can see it,
Everyone else but you,

[Chorus]
[All]
Baby tu light up my world like nobody else,
The way that tu flip your hair gets me overwhelmed,
But when tu smile at the ground it ain't hard to tell,
tu don't know,
Oh oh,
tu don't know you're beautiful,
If only tu saw what I can see,
You'll understand why I want tu so desperately,
Right now I'm looking at tu and I can't believe,
tu don't know,
Oh oh,
tu don't know you're beautiful,
Oh oh,
That's what makes tu beautiful

[Verse 2]
[Zayn]
So c-come on,
tu got it wrong,
To prove I'm right,
I put it in a song,
I don't know why,
You're being shy,
And turn away when I look into your eye eye eyes,

[Bridge]
[Harry]
Everyone else in the room can see it,
Everyone else but you,

[Chorus]
[All]
Baby tu light up my world like nobody else,
The way that tu flip your hair gets me overwhelmed,
But when tu smile at the ground it ain't hard to tell,
tu don't know,
Oh oh,
tu don't know you're beautiful,
If only tu saw what I can see,
You'll understand why I want tu so desperately,
Right now I'm looking at tu and I can't believe,
tu don't know,
Oh oh,
tu don't know you're beautiful,
Oh oh,
That's what makes tu beautiful

Na Na Na Na Na Na Na Na Na Na
Na Na Na Na Na Na [x2]

[Middle 8]
[Harry]
Baby tu light up my world like nobody else,
The way that tu flip your hair gets me overwhelmed,
But when tu smile at the ground it ain't hard to tell,

[All]
tu don't know,
Oh oh,
tu don't know you're beautiful,

[Chorus]
[All]
Baby tu light up my world like nobody else,
The way that tu flip your hair gets me overwhelmed,
But when tu smile at the ground it ain't hard to tell,
tu don't know,
Oh oh,
tu don't know you're beautiful ([Harry:] Oh),
If only tu saw what I can see,
You'll understand why I want tu so desperately ([Harry] desperately),
Right now I'm looking at tu and I can't believe,
tu don't know,
Oh oh,
tu don't know you're beautiful,
Oh oh,
tu don't know you're beautiful ([Harry] beautiful),
Oh oh,

[Harry]
That's what makes tu beautiful

[From: link