Bravo for allowing comment editing, but what's the explanation for enforcing a five-minute window?

I think this might be over-engineering. If I have a spelling mistake or an inaccuracy I'd like to fix, I don't think the fact that five minutes has elapsed should prevent me from fixing it.

Further, if you are worried people will edit their comments in a way that makes the comment thread nonsensical, they can already do this by deleting their comment. So, limiting the ability to edit isn't really helping much in that regard.


If people don't like this idea, I'm definitely open to hearing your reasons. For now, it seems like an unnecessary limitation of a quite awesome feature.

Update 2

Regarding John's scenario...

Me: Obama is cool!
You: You are right, man!

My edit: Obama is an idiot!
You: You are right, man!

...this problem can still occur with deletions...

user1: Obama is cool!
user2: No, McCain is cool!
you: You are right, man!

user1: Obama is cool!
---- deleted -----
you: You are right, man!

So, yes, editing could be abused as you suggest, but discontinuities can occur already because of deletions (and as someone else mentioned, because upvoted comments get prioritized upward).

As for Jeff's argument about rate limiting, I agree that is important, but I don't understand why you can't just use a CAPTCHA to prevent too many edits in a short period of time.

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    I reworked my question to be a feature request, so it is no longer a duplicate (that I know of).
    – devuxer
    Commented Dec 28, 2009 at 20:46
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    Changed the title to reflect this. I still think it's a lousy idea though. There's no revision history for comments, and that makes editing - especially very late editing - problematic.
    – Shog9
    Commented Dec 28, 2009 at 20:50
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    Late deleting is no less problematic (and probably more), however, but that is still allowed. I think the fear that editing will cause users to destroy the continuity of comment threads is unjustified.
    – devuxer
    Commented Dec 28, 2009 at 20:54
  • I voted to close because I still think it's a duplicate of meta.stackexchange.com/questions/25831/…. That's where the five-minute window came from.
    – mmyers
    Commented Dec 28, 2009 at 21:29
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    @DanTheMan: it's not continuity that I'm concerned about. SO doesn't do comment threading, and does cherry-pick up-voted comments for initial display... so continuity is already wrecked in many, many instances. Situations akin to John's example OTOH...
    – Shog9
    Commented Dec 28, 2009 at 21:40
  • @mmyers, just for the record, I don't believe the question you think is a duplicate addresses the issue of why the time limit is desired.
    – devuxer
    Commented Dec 28, 2009 at 21:51
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    Why does this have status "declined" without a rationale given? How do we reopen? Particularly with the new emphasis on being welcoming, this accessibility nightmare really needs scrapping. Commented Aug 15, 2018 at 15:54
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    @DewiMorgan , devuxer, and others: Would it suffice to merely increase the time limit to 10, or maybe 20 minutes? That might be a good middle-ground. Commented Jun 18, 2020 at 22:09
  • @SolomonRutzky Did you even read what we wrote? Slightly increasing the timeout won't resolve ANY of the problems we listed for the usability-nightmare of timeouts. There has, in the DECADE since this was asked, been exactly NO rationale offered for a timeout in the first place, unless you count the fairytale of edit-abuse (zero real-life cases anywhere on the net). So we can't reach a compromise with the "opposing argument", since there isn't one. There's just us, arguing against a user-hostile mechanism that was apparently put in place with no thought, justification or A/B testing. Commented Jun 23, 2020 at 4:49
  • @DewiMorgan I get that you're passionate and frustrated about this issue. But there's no reason to be snippy about my not having time to read all of the answers here (especially with me being mostly, if not potentially entirely, on your side). I didn't know until now that you had posted an answer. So no, I didn't read what you had written. I've been disappointed in the 5 minute timer for years but figured that SO might be more likely to extend the time limit than remove it, so maybe there's a practical limit that's much longer, just not forever. 24 hrs? 72? If not, then ok. I was just asking. Commented Jun 23, 2020 at 5:46
  • @SolomonRutzky Heh - I'm sorry, you're right to say I was snippy. And I agree, raising to hours or days would address at least some of the worse accessibility issues. I suspect the true reason for this timeout is less about edit risks, more about performance and scaling. But the rationale for the decision never has been explained, in the decade of silence on this issue: frustrating, as we then can't even know what suggestions for compromise might help. Commented Jun 23, 2020 at 18:48
  • Just to add my anecdotal experience: I routinely leave comments and then go about my business for the day, and don't notice typos and other sadness in my comments until well after 5m have elapsed. I generally just delete and repost, which is mildly annoying, but gets the job done. I've probably done this at least a dozen times.
    – Him
    Commented Feb 14, 2023 at 15:30
  • What's just plain rude is Stack Exchange allowing you to start editing a comment with no mention of the 5min cap, and then slapping you with it when you hit Save edits. If they're going to put a timer on it, it should be visible and counting down while edits are being made. Also, a 10min grace window would be much more reasonable than 5, if there absolutely must be a limit.
    – Mentalist
    Commented Mar 18 at 8:57

5 Answers 5


Reasons for eliminating the five-minute limit

  • Late changes are sometimes needed and not necessarily due to mistakes. For example, links might rot and have to get replaced by new ones.

  • Comments are supposed to claim a few space as possible. Editing an existing comment, rather than posting a new one, accomplishes that.

  • Right now, if I have to make an important change (e.g., botched link) after the grace period expired, I'm left with two choices:

    1. Post the intended edit as a new comment and delete the existing one.

      This completely breaks the context if somebody has replied already.

    2. Post a second, clarifying comment.

      Again, this clutters the comment section.

  • Typos make the site look ugly and are embarrassing for the poster.

Addressing possible abuse scenarios

  • Chameleon questions are already a problem. If the five-minute limit is removed, chameleon comments might become a problem too, especially since existing responses will lose their context.

    But deleting comments already leaves subsequent comments without a context. Also – as @PopularDemand already said – comments aren't supposed to contain [...] important information, so lost context isn't really something to worry about.

  • As @LadybugKiller pointed out, somebody might change their comment maliciously and put words into a user's mouth if he responded You are right, man!.

    But nobody is actually supposed to respond You are right, man!. That's what comment upvotes are for.

  • Comment upvotes may get misinterpreted after an edit.

    But this is easily fixed by removing all existing upvotes after an edit. Also, undoing comment upvotes is already possible, so this might not even be needed.

  • Comment edit might be used to cloak abuse.

    But this is easily fixed by disallowing edits (and deletion?) after a comment has been flagged as rude or offensive.

  • As @JeffAtwood said, [a]nything that isn't rate limited will inevitably be abused.

    But the current implementation isn't a rate limit; it makes late edits impossible. Limiting the possible comment edits per minute (no CAPTCHAs, please), seems like a better choice to me.

Also, all possible abuse scenarios (that I could think of) are already affected by the current implementation, since comments may get several responses within the grace period.

Revision history and timestamps

@Shog9, @0A0D, @JeffAtwood and @jadarnel27 all mentioned (the lack of) a revision history, which – if implemented – it would render all abuse concerns moot.

If that's too expensive to implement (I assume it would be much more expensive than just abolishing the time limit), maybe it would suffice to just change a comment's timestamp after each edit. That would at least take care of @LadybugKiller's scenario.

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    I think it might be necessary to have a comment revision history if this were in place (like the one for chat messages, for instance). Commented Jun 20, 2012 at 15:42
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    "Late changes are sometimes needed and not necessarily due to mistakes." If the comment was important or worthwhile, the link should have been absorbed into a question or answer as appropriate. Comments are ephemeral; treat them as such. Commented Jun 21, 2012 at 2:06
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    @NicolBolas: Whenever possible, yes. But I can hardly incorporate a link into an answer if I'm trying to prove it wrong.
    – Dennis
    Commented Jun 21, 2012 at 2:18
  • @Dennis: You can prove it wrong in your own answer, either by just obviously being right or by making a argument that the given alternative isn't right. Furthermore, if it is indeed wrong, the link won't have rotted before the answer has received its downvotes and been made irrelevant. Commented Jun 21, 2012 at 2:46
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    @NicolBolas: Wouldn't an answer, posted solely to point out the flaws of an existing answer, be either deleted or converted into a comment?
    – Dennis
    Commented Jun 21, 2012 at 2:50

I am worried about people changing their comments to give a thread (the following comments) a complete new meaning. Making it nonsensical is one of the better things that could happen. Shog9 is right in his comment: there is no history for comments. That's the main problem.

Easy example:

Me: Obama is cool!
You: You are right, man!

My edit: Obama is an idiot!
You: You are right, man!

There are enough jerks out there, who think things like that are funny. They can really mess SO up with that.

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    +1 This should be the accepted answer.. though there is no perfect 'grace period'... 5 mins seems to be the universally accepted standard for comments, questions, and answers for the trilogy sites so any longer would upset the balance - though if there was a revision history then the 5 min rule would no longer apply! Commented Dec 28, 2009 at 21:29
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    I challenge you to find a single location on the net - anywhere - where this has been done maliciously. It's done, occasionally, as a good-natured prank among friends, but I can find no evidence that this is a regularly-abused feature anywhere. Commented Jul 30, 2015 at 19:48

I always find it a little discriminatory that people with fully-working limbs, familiar and comfortable in their language, set their input requirements as if everyone else is in the same privileged position. [Edit2: note that this behavior is fine for defaults - just really bad for requirements.]

What happened to accessibility being important?

For someone who's second-language English, five minutes is barely enough time to check a couple of words, let alone compose full sentences and paragraphs. Why should only those who are fluent be permitted to edit?

Someone who's using text-to-speech or other disability input, who may even commit their comment early by accident, now must flail with their close-to-impossible-to-use hardware before the timeout. Timeouts are a slap in the face to disabled people using such devices!

That I can find, there is absolutely no evidence, anywhere, that the ability to edit comments is more abused if there is no time limit. I honestly cannot find a single scrap of evidence, a single maliciously-edited-after-five-minutes comment, anywhere on the net. Perhaps my Google-fu is weak today, but no: I think this is just that programmers are used to the mindset of adversarial thinking, at the expense of accessibility.

Yes, it might get abused. There is no perfect way to avoid this, and there are systems already in place to deal with that when it happens. Comments can get abused even without editing, and there's nothing new there.

If someone edits their comment, then at least if there is no timeout, people who notice that edit later can edit their own responses in return. So by adding a timeout, you are making it easier and more effective to abuse commenting editing, instead of harder and more pointless.

If editing is worth having - and clearly it is - then it is worth having properly, not a half-assed, unfriendly "well, you can use it to fix a couple of quick typos, but that's IT!" version.

As others have said, I have indeed encountered the timeout elsewhere, and I abhor it in every incarnation: you spend 10 minutes editing your comment with extra, helpful stuff; you click submit... and all your research is lost to an error message telling you that you were too slow. Why? There is no earthly reason, other than to annoy legitimate users.

[Edit: in testing, here, you at least don't lose the edits: they just become pointless, and have to go out of chronological sequence, and you get pointlessly annoyed and have to copy, paste, and repost, and are reminded once again about what appears to be just a poor design decision.]

  • 5
    +1 Good point about users who are learning languages. I hadn't thought about that, but it is true. Since it seems everything on Stack Overflow is in English, many people are having to learn a new language in addition to learning the site-specific markup, which has instructions given in English.
    – ctype.h
    Commented Nov 17, 2012 at 3:26
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    +1 for "Yes, it might get abused. There is no perfect way to avoid this, and there are systems already in place to deal with that when it happens." That's been the rationale behind several other good decisions to change things that didn't work well, and it's a good argument here as well. Commented Jul 30, 2015 at 13:14

Anything that isn't rate limited will inevitably be abused. This is a fundamental law of human behavior.

Remember that comments are lightweight and unversioned.

You might also consider why Digg comments and even Skype chat (where the pencil icon was cribbed from) have the same exact "editable for a small period after creation, then locked in forever" behavior.

  • Jeff, I've read that blog post (and it's good), but why is the solution a time limit rather than a CAPTCHA?
    – devuxer
    Commented Dec 28, 2009 at 22:00
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    @Dan, that's where "lightweight" comes in; comments aren't supposed to contain the really important information anyways. And don't forget you can always delete a comment and write a new one if you really have to.
    – Pops
    Commented Aug 29, 2010 at 17:26
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    rate limiting != time limiting. One is a useful anti-abuse tool, the other is an accessibility nightmare. [edit: enter posts comments? I didn't realize. And now I have only five minutes to finish this comment. I am so glad I am not disabled, and am mostly fluent in English.] Commented Jun 21, 2012 at 19:27
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    Then I think they probably need to get versioned. (Can't moderators already see a comment's history? If they can't, they should. That's important.)
    – Ry-
    Commented Jun 21, 2012 at 19:29
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    @mini constraints help people get things done. If you could live forever, why would you ever have any urgency to get things done, ever? Commented Jun 21, 2012 at 23:43
  • We'd better shut down the site, as that spam is getting unhandleable. Oh wait, no, smokey deals with it, and we deal with problems as they occur... Commented Mar 6, 2017 at 20:16
  • "consider why Digg comments and even Skype chat..." Skype has since fixed this (I just edited a 3yo comment on there to test), but even when they had it, they restricted it to an HOUR, and this was for realtime chat, not for website comments which obviously have a longer cycle time so need a far longer timeout. I wouldn't take UI guidance from Digg: its comments don't seem editable any more, either. Commented Feb 14, 2023 at 20:22
  • @JeffAtwood "@mini constraints help people get things done. If you could live forever, why would you ever have any urgency to get things done, ever?" Why do you feel the need to put artificial urgency on comments? Why would it be bad if someone didn't feel an urgent 5 minute requirement to fix their comments? Commented Feb 14, 2023 at 20:24

At least allow people to complete their edits, i.e. if I started to edit after four minutes, and the edit took two minutes, allow it to go through even though it's one minute after the edit window.

Let's say the post office closes at 5:00 PM. You enter the door at 4:55. When 5:00 rolls around they don't let any new customers in the door, but at least they allow customers already in the post office to complete their transactions!

Sure, I've turned seconds into minutes, and minutes into hours in my example. But I'm sure people understand what I'm saying.

So what happens currently? Can you at least get back out of the door? Yes, but it isn't pretty!

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    Workaround: copy the painstakingly made edit that you suddenly can no longer submit. Paste it into a new comment. And delete the old comment. Commented Mar 16 at 23:51
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    And then explain to all the readers that as they read it they should imagine your comment as if it were placed chronologically between Person J's comment and Person L's comment. Explain that you are actually Person K, and your comment originally resided there, but see, there was this thing that didn't go as planned, and you had to completely delete your comment because of this silly limitation on editing comments and... well yeah, just explain all of that and then everyone will be able to understand your comment in its proper context. It won't disrupt the flow of the comment section at all.
    – Mentalist
    Commented Mar 19 at 2:21
  • Well if I commented, "I forgot the 's' on the word 'places' in the fourth sentence of my previous comment." People would get angrier at me. Commented Mar 22 at 2:40

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