An optical imaging lens includes a first lens element to a fourth lens element. A periphery region of the image-side surface of the first lens element is convex, the second lens element has positive refracting power, an optical axis region of the object-side surface of the second lens element is convex, a periphery region of the image-side surface of the second lens element is convex, the third lens element has positive refracting power, a periphery region of the image-side surface of the third lens element is concave and a periphery region of the image-side surface of the fourth lens element is convex. EFL is an effective focal length, AAG is a sum of three air gaps along the optical axis, T3 is a thickness of the third lens element and G12 is an air gap between the first lens element and the second lens element to satisfy (EFL+AAG)/(G12+T3)≤3.800.