On: Better Box Shadows (CSS)

[numlock86]

> The blur filter is notoriously slow on performance.

I am curious: Do you have some numbers? What is this statement based on? Intuitively I'd agree, but on a technical level I am not so sure.

[mattkrick → numlock86]

We used to blur content behind modals. When the modal animated in, it'd hit single digits fps on a MacBook pro. Ditched it for a more opaque scrim and fps was back at 60.

[littlestymaar → numlock86]

I don't have numbers, but browsers must implement it as a Gaussian blur (because that's what the spec says) which is quite costly.