What's the difference between these two types of plugs? Why do they exist? Why can't all plugs be 3.5mm ?

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    Conversely, why can't all plugs be 1/4"? Commented Mar 16, 2011 at 15:55
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    Don't forget the 2.5mm plug! First come the 1/4" plug. I have seen it in an old manual telephone exchange from 193x. When things got smaller they developed the 3.5mm version, and later the 2.5mm version. The 2.5 and 3.5 versions breaks more easily then the 1/4" since they are smaller.
    – some
    Commented May 26, 2011 at 4:46

4 Answers 4


Different form factors allow use for different applications - I believe they are capable of carrying the same signals. 1/4" cables are more durable - I've bent many mini jacks.

The thing to be aware of is that there is professional line level and consumer line level, so you need to make sure your equipment is calibrated to work together.

From your picture, the cable on the left is stereo (trs) and the right is mono (ts) - you can tell by the black bands on the tip. If the 1/4" had the two bands, it could be stereo or a balanced mono cable, depending on how you use it.

See here for some detailed info and history:



I do not know of any meaningful electrical difference between them at the line- or instrument-level voltages that they usually carry.

I believe the 3.5mm plug was created to be a "miniaturized" version of the 1/4" plug, which was already in general use. 3.5mm is more commonly seen in consumer electronics, and it's usually a TRS plug (for "Tip-Ring-Sleeve"), which is sometimes called "stereo," as opposed to TS ("Tip-Sleeve") or "mono."

I generally see 1/4" plugs used more often in audio production - instrument cables, hardware inputs and outputs, and headphones. I think this is largely due to tradition, but I must say that I generally prefer the larger plug if I'm frequently plugging and removing cables because it feels a little bit more stable to me. 3.5mm plugs require a more precise mechanism because of the smaller size, which strikes me as more delicate.

The Wikipedia link in Sam's answer is also excellent.

  • Yea the 1/4" plug does feel more durable. It would be funny having them on an iPod though :)
    – 7wp
    Commented Mar 16, 2011 at 16:23
  • I don't think apple would find it funny - it would take up too much space inside the device - which is why the mini plug is created. If you look inside some of your electronic, check out the volume which is taken up by each jack. The 1/4" is huge, whereas the mini takes up much less space. Why can't they all just use bluetooth? ;)
    – Sam Greene
    Commented Mar 16, 2011 at 16:50
  • Oh yeah, I think the 3/5mm plug makes WAY more sense on devices like iPods or CD players or walkmans or whatever. But this isn't about whether one plug is better than another - clearly they both have their fans in different areas! Commented Mar 16, 2011 at 16:57
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    There's a lot to be said here for tradition and how standards endure, not because they're the current best, but because they're the current ubiquitous way of connecting things together. The 1/4" type connector is a good example of that.
    – Ian C.
    Commented Mar 16, 2011 at 21:19

I don't know anyone who has actually noticed an audio difference between 1/8" and 1/4" jacks on their headphones. In fact many higher end headphones come now with adapters! That said, the big difference between the 1/4" and the 1/8" jacks comes from usability. As another responder already mentioned when things were miniaturized they had to drop the jack size.

The 1/4" jack is the primary (unbalanced) jack of choice for the music industry while the 1/8" jack is king in personal electronics. Primarily is durability: a 1/4" jack and larger cable will break/bend less often than a small wire and jack. I can't tell you how many 1/8" jacks I have accidentally managed to bend in my luggage or storing because I wasnt as careful with it as I should have been (especially with heavier equipment). Another reason for the 1/4" jack is IMPEDANCE MATCHING. Impedance matching is not as important now as it used to be in the past when setting up an audio system, but you can run more power through a larger jack than you can a smaller jack.

Here's an AV post that explains Impedance Matching really well: http://nwavguy.blogspot.com/2011/02/headphone-impedance-explained.html

Getting into the idea of wireless headphones and whatnot, they are okay however there can be alot of interference with wireless/bluetooth devices. Just take a speaker or headphone near an electrical cord/ power strip. That "datdatdat" sound/buzz you hear is interference from an induced electro magnetic field around the power strip which affects the magnetic coils inside your cans (headphones) or speakers (unless you have everything shielded)

TL;DR If you are using portable audio equipment or using it less heavily you can get away with 1/8". If you are a heavy user or are doing alot with audio you want to look at 1/4" and XLR (another topic entirely).

Oh, and its easier to adapt from a 1/8" jack to 1/4". Going the otherway can be troublesome and if you get a direct or straight adapter instead of a wired adapter you can wallow out your headphone jack-port quickly.


Larger plug is more durable, and less prone to having bad contact - because its contact surface is so large.

Otherwise, for smaller devices like smartphones etc, the 1/4" jack would be too big - so a smaller 1.8" (3.5mm) connector has been developed, as well as even smaller ones.

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