String buzz happens when a string vibrates against a fret instead of above it

Guitar string buzz is the rattling or metallic sound you hear when you play a note and the string makes contact with one or more frets below where it should be vibrating freely. This is one of the most common problems new and experienced players encounter, and the cause is almost always one of three things: the neck is too flat, the strings are too low, or a single fret is higher than its neighbors.

The good news is that buzz is fixable. The bad news is that the fix depends on what caused it. A truss rod adjustment might solve it. A bridge shim might solve it. A fret leveling job at a repair shop might be necessary. Before you spend money, you need to know which one you're dealing with.

Key Takeaways

  • Buzz usually comes from one of three sources: insufficient neck relief (the neck is too straight), action that is too low, or a single fret that is higher than the others.
  • You can check for neck relief yourself by sighting down the fretboard with the strings at playing tension, looking for a slight curve from headstock to body.
  • Adjusting the truss rod is a free fix if the problem is neck relief, but turning it the wrong direction can damage the neck, so research your specific guitar's truss rod first.
  • If buzz happens only on certain frets or only on one string, the problem is usually a high fret, which requires professional fret leveling.
  • Raising the bridge or nut slightly is the safest first step if you are unsure of the cause.

How to check if your neck has enough relief

A guitar neck should have a very slight forward curve, called relief. This curve gives the strings room to vibrate without hitting the frets in the middle of the neck. If the neck is too flat or bowed backward, the strings will buzz.

To check your neck relief, hold the guitar as if you are playing it. Press the first string down at the first fret and at the last fret at the same time. Now look at the gap between the string and the frets in the middle of the neck—around the 7th or 8th fret. There should be a small gap, roughly the thickness of a credit card. If the string touches the frets or if there is no visible gap, your neck is too flat.

You can also sight down the fretboard from the headstock end, looking along the edge of the frets as if you are aiming down a rifle barrel. A healthy neck will show a very slight curve. A flat neck will look like a straight line. A neck with too much relief will show a noticeable hump in the middle.

Adjusting the truss rod to add neck relief

Most guitars have a truss rod inside the neck that can be tightened or loosened to adjust the amount of relief. Tightening the rod pulls the headstock forward and flattens the neck. Loosening the rod allows the neck to bow forward and adds relief. The truss rod nut is usually located at the headstock or at the body end of the neck, under a cover plate.

Before you touch the truss rod, find out which direction is which for your specific guitar. Some rods tighten clockwise, others counterclockwise. Turning it the wrong way can snap the rod or crack the neck. Look up your guitar's manual or search "[your guitar model] truss rod adjustment" to confirm the direction.

If you do adjust it, make very small turns—no more than a quarter turn at a time. Loosen the strings slightly first so there is less tension on the neck. Turn the rod, then retune and check the relief again. Wait a few minutes between adjustments so the wood can settle. If you are not confident doing this, a repair shop can do it for $30 to $60.

When buzz is caused by low action

Action is the height of the strings above the fretboard. If the action is too low, the strings will buzz even if the neck relief is correct. This usually happens because the bridge or nut has worn down, or because someone filed them too low.

You can raise the action by shimming the bridge—placing a thin piece of wood or plastic under it to lift it slightly. For acoustic guitars, this is a job for a repair shop because the bridge is glued on. For electric guitars with adjustable bridges, you can often raise the bridge saddle yourself by turning screws or loosening and repositioning the saddle. Check your guitar's manual for the exact method.

If the nut is too low, that is a repair shop job. A luthier can file a new nut or shim the existing one, usually for $50 to $150 depending on the guitar.

Identifying a high fret

If buzz happens only on one or two frets, or only on one string, the problem is usually a single fret that is higher than its neighbors. This can happen from wood shrinkage, impact damage, or a manufacturing defect.

To find a high fret, place a straightedge (a ruler or a level) across the frets and sight along it. You will see small gaps under most frets, but if one fret touches the straightedge while others do not, that fret is high. Mark it with a piece of tape.

A high fret requires professional fret leveling. A luthier will sand the frets level and then re-crown them so they all make contact with a string at the same time. This job costs $100 to $300 depending on how many frets need work and the guitar's value.

Buzz on open strings versus fretted notes

If buzz happens only when you play open strings, the problem is usually the nut. The nut slots may be cut too deep, or the nut itself may be too low. This is a repair shop job.

If buzz happens only when you fret notes, the problem is usually neck relief or action. If it happens on all fretted notes across the whole neck, adjust the truss rod or raise the bridge. If it happens only on certain frets, you likely have a high fret.

When to take your guitar to a repair shop

Take your guitar to a luthier if the buzz does not go away after you adjust the truss rod, if you are uncomfortable adjusting the truss rod, if buzz happens only on certain frets, or if raising the bridge does not help. A good repair shop will diagnose the problem in minutes and tell you what it will cost to fix.

Expect to pay $50 to $100 for a diagnosis and setup adjustment. Fret leveling costs more. If your guitar is inexpensive, you may decide the repair is not worth it, and that is a reasonable choice. If your guitar is one you play regularly, the repair is usually worth doing because buzz makes the instrument unpleasant to play.

Frequently Asked Questions

Can I damage my guitar by adjusting the truss rod?

Yes. Turning the truss rod the wrong direction or turning it too far can crack the neck or snap the rod itself. Always look up your specific guitar model first to confirm which direction tightens and loosens the rod. Make quarter-turn adjustments only, and wait a few minutes between turns so the wood can settle.

Why does my buzz go away when I play harder?

When you play with more force, the string vibrates higher above the frets. If the buzz stops when you dig in, it usually means the action is too low or the neck does not have enough relief. Raising the bridge or adjusting the truss rod will let you play normally without buzz.

Is string buzz always a sign something is wrong with the guitar?

Not always. New strings sometimes buzz for the first few hours until they settle. Old strings can buzz if they have lost their roundness. Try replacing the strings first. If buzz continues with fresh strings, then the guitar itself needs adjustment.

Can I fix buzz by tightening the strings?

Tightening the tuning pegs will not fix buzz because it does not change the action or neck relief—it only raises the pitch. The string will still vibrate at the same height above the frets. You need to either adjust the neck, raise the bridge, or fix a high fret.

What is the cheapest way to fix buzz?

If the problem is neck relief, adjusting the truss rod is free. If the problem is action, shimming the bridge is cheap—a few dollars for materials. If the problem is a high fret, professional fret leveling is the only fix, and it costs $100 to $300. Start by checking neck relief and trying a small bridge shim before paying for fret work.