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

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

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

[Verse 2]
[Zayn]
So c-come on,
u 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 u light up my world like nobody else,
The way that u flip your hair gets me overwhelmed,
But when u smile at the ground it ain't hard to tell,
u don't know,
Oh oh,
u don't know you're beautiful,
If only u saw what I can see,
You'll understand why I want u so desperately,
Right now I'm looking at u and I can't believe,
u don't know,
Oh oh,
u don't know you're beautiful,
Oh oh,
That's what makes u beautiful

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

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

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

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

[Harry]
That's what makes u beautiful

[From: link