Note: I am not asking why is there a minimum limit.

Previously closed as dup, but neither of the "duplicates" answer this question!!!

The suggested dups were:

Both of which ask why the limit is there. I know why it's there. I'm happy it's there.

This question is asking why it is 15 (and not 14, or 16, etc)?

Was any thought or research put into the choice, or was it just based on feel?

Some examples of reasons for choosing 15:

  • Was some statistical analysis done on comment sizes?
  • Was the limit borrowed from an external academic or commercial source?
  • Was it decided on by committee?
  • Is it because it's the largest length that can be represented by a single hex digit?

Also note: I don't think it's a bad limit or needs changing. I am just curious to know why 15 specifically was chosen.

The reason I'm asking is if the reason has firm basis it, that basis could be valuable info for someone researching lower thresholds of meaningful communication.

  • 23
    Unicorns fly in groups of 15. Thought it was obvious :)
    – Fluffeh
    Apr 3, 2014 at 9:38
  • 5
    "spolsky atwood" is 15 bytes long (including the NUL character). Apr 3, 2014 at 9:38
  • 4
    @Łukasz, [questioner is] not asking why is there a minimum limit. Apr 3, 2014 at 9:47
  • 3
    @FrédéricHamidi but the answer to that questions gives an explanation: because 15 is mentioned in some holy quote from Jeff. Quotes from Jeff are considered holy because unicorns talk to him when he sleeps or something that way... Apr 3, 2014 at 9:50
  • 1
    why is the max comment length 600
    – Bolu
    Apr 3, 2014 at 10:39
  • 2
    Guys, I'm asking why was 15 chosen. Those dups do not ask or answer that
    – Bohemian
    Apr 3, 2014 at 10:45
  • 3
    It's the median age of emotional maturity of users on the site. Not sure if that's why it was picked, but just sayin'
    – Tim Post
    Apr 3, 2014 at 11:37
  • 1
    @TimPost Maybe it's the median IQ of users on the site.
    – devnull
    Apr 3, 2014 at 11:48
  • 3
    @TimPost ...Is not!
    – Bohemian
    Apr 3, 2014 at 11:49
  • 9
    I have a feeling the only serious answer here is "no special reason". Just a moment decision by Jeff when he wrote the code. Apr 3, 2014 at 11:55
  • 6
    @ShadowWizard et al., the answer to "Why this particular number?" is almost always "Because we had to pick one and this one felt about right." The answer to "Why a minimum at all?" is more interesting and addressed in other places. Apr 3, 2014 at 20:13
  • @DavidFullerton Sure, but I am curious if any thought or research went into it.
    – Bohemian
    Apr 3, 2014 at 20:46
  • 1
    @ShadowWizard you seem to doubt that Jeff really spoke with unicorns in his dreams ;) Apr 3, 2014 at 20:56
  • 1
    @ShadowWizard I don't really talk to Jeff on a regular basis, and it seems a little silly to send him an email about this :) If there was research, it was probably of the form "What are some crappy comments we don't want to allow?" and set it just longer than that. But probably he just picked a number. Apr 4, 2014 at 15:29
  • 2
    Thanks @David, your reply is more than what most here expected, I'm pretty sure of that. As for email asking "Hey Jeff, why did you set the minimum comment length to 15?" he'll go after you with some giant letter (maybe T for trivial? ;)) so better not push your luck. Apr 4, 2014 at 20:14

1 Answer 1


I am asking why it is 15 (and not 14, or 16, etc)?

Perhaps because 15 is the magic constant of the unique order-3 normal magic square.

Seems like a good enough reason!

Moreover it is a:

  • 1
    Ah, it's a magical number. I thought so. Apr 3, 2014 at 10:47
  • I have no idea what a magical number has to do with minimum comment length limitation...
    – Bolu
    Apr 3, 2014 at 10:58

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