The right time to replace strings varies from player to player. Whether you play an acoustic or an electric guitar, arbitrary rules like ‘change strings after every 100 hours of play’ are rarely going to hit the spot.

The best approach is to learn to recognise the signs that a string change is in order. This way you can replace them when they actually need to be replaced. Here are some common indicators. Look out for them and you’ll soon find your own rhythm for string changes:

1. The strings are discoloured and dirty

This is the easiest sign to recognise. Strings turn black from the oils and sweat on our hands and as a result of the moisture in the air. They also collect dirt, particularly on the underside of the strings and between the windings of wound strings.

Run a tissue along the underside of your strings and see how much grime has collected!

2. The strings’ sound has lost its ‘brightness’

New strings have a wonderful crisp, resonant, and clearly defined sound. Clean strings vibrate more freely and for longer, resulting in a longer sustain. 

Dirt on strings dampens vibration and sustain. This dampening filters out higher frequencies. Notes and chords sound duller and more one-dimensional as strings get past their prime—not something any guitarist wants!

3. The strings show signs of damage

If you see a kink in a string, it is at greater risk of breaking. You can sometimes also see that the underside of a wound string has been flattened from repeated contact with the fret below it (particularly on bass guitars). This is also a sign that the string is in need of replacement.

Wound strings that show signs of unwinding (usually at the saddle or bridge) should also be changed. It won’t be long until they break.

4. You break a string

There are a number of reasons why a string might break, but one is simply that the strings are old. As the moisture on strings (from our hands and from humidity) reacts with the air, a process of oxidation takes place eventually resulting in corrosion. Oxidation makes a string harder, more brittle and less flexible. This is why older strings feel stiffer, have poor sustain (they don’t vibrate as freely) and are more prone to breakage.

If you break a string, and your strings are not brand new, change the whole set. If you’ve broken a string on a brand new set, there are likely other factors at play.

5. You’re having difficulty tuning a string

Old strings can be difficult or even impossible to tune. A tell-tale sign of this is if, when tuning with an electronic tuner, the note seems to fluctuate randomly above and below the desired pitch (make sure the battery in your tuner is still good though, if it has one) and the tuner doesn’t seem to be able to ‘find’ the note.

If you can tune a string but it won’t hold its tuning, there could be issues with the nut or machineheads.

Thinking about the state of your strings? Check out our advice on prolonging string life.