I was wondering if I can use a CAT5e keystone jack with CAT6 cable. I am refering to the parts that terminate a cable where it comes out of the wall.

I want to run a 30 ft length of CAT6 but all I have is CAT5e jacks and I don't want to buy any news ones if I don't have to.

I had read somewhere that CAT5e is 100mhz and CAT6 is 200mhz (though I could have sworn CAT6 was 350mhz).

Anyhow any assistance would be appreciated.


6 Answers 6


From Wikipedia:

Category 6 cable, commonly referred to as Cat 6, is a standardized cable for Gigabit Ethernet and other network physical layers that is backward compatible with the Category 5/5e and Category 3 cable standards.

You can always use a lower standard cable or jack, but you will be limited by the speeds of the slowest link in the chain.

  • Ok see that is what I was wondering, whether or not the 5e jacks would impact the speed of the cable since the jack built pretty much the same I would imagine. Commented Oct 22, 2013 at 15:18
  • 1
    No, it is not. CAT 6 connectors are different and the they have pins in zig-zag order Commented Oct 22, 2013 at 15:22
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    The only difference between Cat5e and Cat6 is the way the cable is made (Cat6 is more twisted and with better shielding). RJ45 terminators made for Cat5 may not fit Cat6 cable due to the thicker size of copper strand, but the pinouts are the same for both cables. See the diagrams here vs here for a comparison. This site has a good explanation of the differences within the cables.
    – techturtle
    Commented Oct 22, 2013 at 16:21
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    @Shiro If you have a connection that is Cat6 Jack--Cat6 Cable--Cat5e Jack you will be limited to the speed of the slowest piece, namely the Cat5 jack. To ensure full Cat6 speeds, each piece in the connection has to be to the same standard as all the others. Theoretically, anyway... I'm not sure how much of a difference a single jack can make. But if speed is essential, make sure they all match.
    – techturtle
    Commented May 4, 2018 at 5:41
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    @techturtle I don't know if I agree that the cat5e Jack will noticeable impact speeds. Electrically, the reason why cat5 is slower than cat6 is that it is less insulated from noise (thickness of cables and shielding). How is a cat5 jack constructed differently than a cat6 jack that a cat5 jack is "slower". I would guess that, electrically, the couple of mm of metal the signal goes through in the jack itself doesn't impact the signal much one way or the other.
    – Philip
    Commented Jul 14, 2018 at 4:04

Cat6 conductors are thicker (typically 23 AWG) than Cat5e conductors (typically 24 AWG).

As someone already pointed out, Cat6 plugs arrange the conductors in a staggered pattern because they can be too thick to fit side-by-side.

As far as jacks go, the thicker conductors of Cat6 cable may or may not fit in the IDCs (Insulation Displacement Connectors) of a Cat5e jack.

Most keystone-style jacks use either LSA-Plus (aka Krone) or 110 IDCs (or a very common new hybrid that accepts both types of punchdown tools). In theory both are compatible with wire up to 23 AWG (2.5mm²).

That said, there's no guarantee that every manufacturer abides by every specification of every standard but I can say that so far, the various Cat6 cables I've been using have punched down cleanly into the various hybrid-IDC Cat5e (and Cat6) jacks that I found on Amazon and elsewhere.

However, if you're building a certified network that has to operate at the highest spec possible then you're probably not shopping for parts at Amazon. You're probably using wiring, tools and connectors designed to work together as a system, probably provided by an integrator or a large company like Belden or Panduit.

The rest of us will just punch our jacks and take our chances.

Would my jacks pass a certification test? I don't own any fancy test equipment so I don't know, but they pass data with adequate speed and that's good enough for me.

Your mileage may vary.


I would use cat 6 connectors which cost more than the 5e, assuring me of better speed. Also the wall modular female jacks should be of cat6, just to be sure. Better spend a few extra as you already have invested in cat6 cable. maybe you could sell off the 5e to friends or use them to build wire connectors for single computers/slow devices. goodluck!

  • 2
    You aren't going to lose any speed using cat5 connectors on cat6 cable. Commented Feb 16, 2018 at 12:54
  • @imperium2335, yes you most certainly will. This can be verified with just about any fluke networks verisiv or dtx cable analyzer. Commented Mar 26, 2020 at 20:32

Yes. The RJ45 plug is standard and may only have a different coating on the pins to make it a Cat6 compatible vs. Cat5. You probably won't receive the same speed as if you were using a Cat6 compatible jack.

Doing it this way also denies the ability to call it a Cat6 network though so if you don't care about verbiage technicalities, you are good to go.

  • Well this is for my house just to bypass the old CAT5/e in the wall that has not worked well for me. Commented Oct 22, 2013 at 15:19
  • You'll be fine using it.
    – Travis
    Commented Oct 22, 2013 at 18:36

No. Although I used CAT5e jacks to a CAT6 cable, I couldn't have a connection even if my RJ45 cable tester shown that the pins were connected the right way. The issue was solved when I bought CAT6 jacks. Apparently, no comment about speeds.


Typically, it's up to the RJ45. From what I've seen, CAT6 RJ45 usually uses an insert to aid in placing the wiring. It's easier to fail sticking a CAT6 cable into a CAT5e RJ45, mostly due to the thicker gauge and the crimping not being strong enough to pierce the insulation.

It's possible, but depends on the quality of the RJ45.

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