This is a great question that comes up all the time with new, and even experienced guitar players. The question of if you should change your strings immediately when getting a new guitar has two distinct parts to it. The first is questioning how old the strings are that are on it, and how much use have they seen if any. The second is are factory strings any good, at least good enough to keep on your new baby for a couple weeks.
Read my main article: A Visual Step-by-Step Guide to Changing Acoustic Guitar Strings
These are my go-to Strings for Electric and Acoustic
D’Addario Nickel Wound 10-46 Electric Guitar Strings, 3-Pack, Amazon
D’Addario Phosphor Bronze 12-53 Acoustic Guitar Strings, 3-Pack, Amazon
Where did you buy the guitar?
If you got your guitar from an online retailer, or special ordered it through the store, then those strings are pretty much brand new. Before a guitar goes out the door from the factory, it gets strung and setup. Sure, they’re not going to be using the most expensive strings as their defaults, but they’ll be just fine and do the trick no problem.
Did you buy the guitar from a shop, or used in any way? In that case, you’ll want to change those strings. One of the biggest enemy of string life is use. When you play the guitar, the oils from your fingers get into the string windings, or on the surface (for non-wound strings) and degrade the metal. This causes your strings to start sounding dull, not hold a tune, and not hold consistent intonation. But before you go chopping those strings off, ask the shop you bought it at if they have been changed recently. Or even better, ask them to put a fresh set of strings on the guitar before you buy it. Trust me, any shop I know of would be more than happy to throw in a quick string change for free to insure the sale of a guitar. This shows great customer service, so do not be afraid to ask for that!
How old are the strings?
While the leading cause of string degradation is contact with skin oils which cause corrosion, time and moisture will do the same given enough freedom. That is to say that a brand new set of strings, tensioned and out of the package, will probably last 4 or 5 months before really needing to be changed. Often, guitars will sit in a warehouse for months before being delivered to a guitar shop, and most of the time those strings are still pretty fresh when they come in. If you suspect that the strings have been on the guitar longer than 4 or 5 months, you should probably just change them.
Are factory strings really that bad?
My opinion is no, most guitar manufacturers use nice strings right out of the gate. Especially premium “Made in America” brands like Martin, or Taylor. Martin puts either Martin SP Phosphor Bronze or Lifespan SP strings on their guitars, and Taylor uses Elixir for theirs. Some low end guitars may have low end strings on them from the factory, if this is the case then consider having them replaced. However, any guitar $500 and up is going to have a decent set of strings on it.
Is the guitar set up for the strings you want?
Now this is a very important question. If you’re looking to swap strings, to a different gauge or type then there a some other considerations. The most common situation I saw was an electric player wanting to replace the factory strings with a heavier gauge. If the string is much bigger than about about 50 (which is .050”) then you’ll need to have the nut filed out to accommodate the bigger string. Don’t try to force too big of strings onto a guitar. You can pretty easily crack a nut in half by doing this. Also, make sure that the shop you’re having do the work has a competent guitar tech. Nut work isn’t rocket science, but it does take a steady hand and some know how to cut a nut properly. But that’s not all! If you’re changing string gauges there’s a very good chance that the guitar needs to be setup as well. Even a change from 10s to 11s on a guitar changes the tension on the neck and bridge and will require adjustments. Guitar setups are an incredibly valuable skill to know, but until you’re ready to do the work on your own, make sure you’re bringing your guitar to a tech who knows what they’re doing. And hey, if you ask nicely they might show you a thing or two about the setup work they’re doing.
I also mentioned string type here. A common example is going from standard acoustic strings (light: 12-54) to a flexible core of the same gauge. Even though the gauge is the same, the tension is different which requires a setup.
So Should You Change the Strings on a New Guitar?
Do they sound dead, look corroded, or feel gunky? Then yes.
Do they look shiny and new, feel smooth, and sound good? Then keep them on until they need a change. Just remember that if you decide to switch up the type or gauge of strings you’re using then make sure to have the guitar setup by a competent tech.
I’m pretty boring when it comes to strings that I use, but these have never let me down. For most of my acoustics, I use D’Addario EJ16 Phosphor Bronze Acoustic Guitar Strings (12-53). I buy these things in bulk and change strings often. For most electrics including my Fender Strat, and Gibson ES-137, I use the D’Addario EXL110 XL Nickel Wound Electric Guitar Strings (10-46).