Low action makes fretting easier, but if it's too low the strings buzz. High action feels stiff and can pull notes sharp. Getting it right depends on the neck, the frets and your playing style.
Before you touch the bridge, check two things in order:
- Neck relief. Too much forward bow raises the action in the middle of the neck. Fix relief first.
- Nut height. If the first few frets feel hard but the rest is fine, the nut slots may be cut too high. That's a tech job.
Lowering action on an electric or bass:
- Tune to pitch.
- Measure at the 12th fret with a small ruler.
- Lower each saddle, or each side of the bridge, a small amount at a time.
- Retune and play every string up and down the neck, listening for buzz.
- Stop when buzz starts, then raise slightly.
- Recheck intonation afterward.
On acoustic and classical guitars, the saddle sits in a slot and must be shaped or replaced to change height. Lighter strings can also make an acoustic feel easier without changing the action.