Light swing metronome
Keys: Space start/stop · T tap · ↑↓ tempo ±1, Shift ±5 · ←→ between beats, Enter to cycle
Two clicks per beat in 4/4 at ♩ = 120, with Swing set to Light. The second click falls 58% of the way through the beat, just after the halfway point. That gives the pair a small long-short difference while the main beats stay evenly spaced.
Play a short line of eighth notes, then compare Light with Straight at the same tempo. Listen to the offbeat moving later. Try Triplet as well to hear a more pronounced difference between the two parts of the beat.
Light is a fixed setting in this metronome, not a prescribed ratio for a particular style. Use it as a reference and listen to the musicians or recording you are working with. Swing is available only when Clicks per beat is set to 2.