What should be done with comments on questions after the questions were edited and the comments are no longer relevant?

  • On one hand, these comments are not needed anymore
  • On the other hand - they helped formulating the question as it is. Moreover, the comment discussion may be long, and if one party removes own comments, the discussion will make no sense (until the other sides remove their comments as well).

As the comment poster - should such comments be left alone or should I remove my comments?

  • $\begingroup$ I always ask the other commentors that they should delete their obsolete comments, too; most often they do this, at least in clear cases (misunderstandings, for instance). Flagging is another option. $\endgroup$
    – Raphael
    Commented Apr 22, 2012 at 11:05
  • $\begingroup$ Just note that flagging comments won't get a speedy response until Comp Sci has it's own mods, after we do you'll see flags handled a lot faster. $\endgroup$
    – Ben Brocka
    Commented Apr 23, 2012 at 13:04

3 Answers 3


Comments are ephemeral by design. Don't worry about breaking a discussion thread if you're removing comments of yours that are obsolete. You may flag others' obsolete comments while you're at it, or flag the post if there are a lot of obsolete comments to remove.

I do agree that comments that give general advice on how to formulate the question have lasting value, so I tend to leave them unless there are more important comments on the same post.

A guideline to how many comments are too many is that the important comments should be visible without having to click on “show X more comments”. When the button appears, start pruning.


Deleting obsolete and resolved comments is the accepted practice on this network.

Should we delete obsolete and resolved comment threads?

Comments are like Post-It notes to leave little notes to the author asking for clarification, or to point out problems, or otherwise help make a post better. Ideally, this information should be moved into the post and the comments deleted. Don't leave them around so everyone who comes after has to scan them to see if they are still relevant. It just makes for unnecessary noise and a poor end-user experience.


Some moderators seem to have overlooked “obsolete” in this “delete obsolete comments” policy.

In this question, comments on the question contained new information which was not subsequently included in the question. Someone removed the comments nevertheless, and made part of my answer incomprehensible as a result.

I do not mind if moderators remove obsolete comments, but they should remove only obsolete comments.

Gilles, who deleted the comments I referred to, commented on this answer, and explained that it is easy to deduce that my answer on the main site refer to some deleted comment, and therefore the deletion of the comments did not make my answer incomprehensible. That might be true.

However, I still think that he should have incorporated the comments into the question if he would like to delete them. In my opinion, the deleted comments were much more relevant to the source of the confusion of the asker than the body of the question itself. This is why I posted an answer to the question which was not really explicitly asked. (By the way, I also answered to the question on surface, but this is only because I thought that ignoring the question on surface might be impolite.)

If my answer is viewed independently of the question, it might be fine. But Stack Exchange is not just a set of facts; it is a set of pairs of question and answer, where people can post better answers to the questions later. Now that the comments are gone, the question and the answer are no longer related. I do not think that this is how Stack Exchange is supposed to work.

  • $\begingroup$ I'll own up: I'm the one who deleted the comments. I was alerted by comment flags, and did my best to track which comments were obsolete and which weren't. Apparently I goofed, but even seeing the deleted comments, I don't understand which one you refer to in your answer. Furthermore, I don't see how this makes your question “incomprehensible”. (I don't understand your answer, but this is due my ignorance of the subject matter.) In any case, jimmy himself might have deleted his comment; you can never assume comments to be eternal. If the text of a comment is vital, include it in your answer. $\endgroup$ Commented Aug 21, 2012 at 22:01
  • $\begingroup$ @Gilles: If that is the official policy, I would rather not post an answer in response to a comment. $\endgroup$ Commented Aug 21, 2012 at 22:03
  • 1
    $\begingroup$ The policy is built into the Stack Exchange engine: comments can be removed by their author at any time, and there's no trace of the deletion. People can also delete their answer. You shouldn't write an answer that depends on things like this that should go away: answer the question. If a comment is relevant to understanding the question, it's best to edit it into the question immediately. But again, I don't see how your answer has been made “incomprehensible”. It looks self-contained to me, insofar as I can understand it at all. $\endgroup$ Commented Aug 21, 2012 at 22:12
  • $\begingroup$ My answer looks as if I got some belief about what the asker wanted to ask, out of nowhere. My point is that the comments should not have gone away, so your argument “You shouldn't write an answer that depends on things like this that should go away” is invalid. $\endgroup$ Commented Aug 21, 2012 at 22:24
  • $\begingroup$ No, your answer looks like it's referencing a comment that was not deleted. Since the content of the comment is not useful in understanding the answer, there is no problem. $\endgroup$ Commented Aug 21, 2012 at 22:26
  • $\begingroup$ “No, your answer looks like it's referencing a comment that was not deleted.” Which comment are you talking about? The only comment by the asker which was not deleted is the comment “Thank you for your nice answer” on my answer. $\endgroup$ Commented Aug 21, 2012 at 22:34
  • $\begingroup$ Sorry, I meant “your answer looks like it's referencing a comment that was deleted”. $\endgroup$ Commented Aug 21, 2012 at 22:34
  • 1
    $\begingroup$ And, to reiterate: this was a mistake. I checked whether the comments were obsolete, but apparently failed to notice that there was some information that had not been edited into the question, otherwise I would have either left the comment or edited the question. But you are making a mountain out of a molehill: there is no comprehension problem between the question and the answer. $\endgroup$ Commented Aug 22, 2012 at 0:21
  • 1
    $\begingroup$ I do not think that that is an acknowledgment of mistake. You are basically saying it was my fault on relying on comments, and with that attitude, I do not think that you will learn to avoid the same mistake in the future. $\endgroup$ Commented Aug 22, 2012 at 0:24
  • 1
    $\begingroup$ I flagged most of the comments in the question, but I'm sure I left more than 2 untagged. I also tried quite aggressively to transfer all the relevant information from the comments to the question (and made a mistake at first at that). I follow the guideline that comments are like postit notes, but I also should have been more careful. However, I think it's much easier to follow and understand a question/answer if I'm not required to read any comments. I agree with Gilles that an answer shouldn't rely on a comment. In your answer, I think it would be best to edit in what the comment was about. $\endgroup$
    – Juho
    Commented Aug 22, 2012 at 10:10
  • 1
    $\begingroup$ @Juho: Do not expect too much on others. If you want to delete comments, do your job properly. $\endgroup$ Commented Aug 22, 2012 at 14:35
  • 2
    $\begingroup$ I'm 100% with @Gilles on this one. You should not post answers based on comments. If a comment clarifies a question such that you have an answer, you should see to it that the question is updated to reflect this. Any "answer" which only answers a comment and not the original question should be another comment. $\endgroup$
    – Patrick87
    Commented Aug 22, 2012 at 16:28
  • 1
    $\begingroup$ @Kaveh I don't think I'd automatically grant the premise that comments are for clarifying questions, at least not in the sense you intend. IMHO, any new information which should be a permanent part of the question and which should inform answers to the question belongs in the question text, not in the comments. Comments about required clarification should eventually be deleted. Not all comments should eventually be deleted, but comments asking for & giving clarification should always eventually be deleted as obsolete, once the question/answer is amended. $\endgroup$
    – Patrick87
    Commented Aug 22, 2012 at 22:20
  • 2
    $\begingroup$ @Patrick87, please see this. If you are removing comments you should transfer the relevant information into the question, if you are not going to do so don't remove comments. They are not obsolete as long as they are not incorporated into the question. $\endgroup$
    – Kaveh
    Commented Aug 22, 2012 at 23:09
  • 1
    $\begingroup$ Mistakes happen even though we don't want to. Geez. $\endgroup$
    – Raphael
    Commented Aug 28, 2012 at 9:56

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .