As we announced on Meta Stack Overflow, we are kicking off a project to begin tackling the issue of outdated answers. That post goes into detail on the initiative and our approach.

We are focusing our initial research efforts on Stack Overflow, and not on other sites on the Stack Exchange network. We understand that the issue with outdated answers is not exclusive to Stack Overflow and other technical sites may have similar issues.

However, none of the other sites operate at the scale of Stack Overflow:  more than 31 million answers, compared to 11 million for the rest of the network. And Stack Overflow is our oldest site, so it is the site where the pain is most acute.

Rather than trying to shoot for a one-size-fits-all solution that may actually fit none, we are laser-focused on uncovering the Stack Overflow use cases and coming up with initial solutions that work really well for Stack Overflow. 

We are optimistic that many of the learnings from Stack Overflow will also be relevant and helpful for similar issues faced by other sites on the network. As we get further down the road, we will evaluate whether the Stack Overflow solution can also work for other sites and solicit your feedback here on Meta Stack Exchange.

With this in mind, feel free to share any initial thoughts on how you've experienced outdated answers on other Stack Exchange sites and any ideas you have about ways to attack this problem. 


6 Answers 6


Over on Arqade we often handle outdated answers by posting a bounty on the question with the "Current answers are outdated" reason. When doing so, we may post a comment on one or more of the existing answers as well (normally just the accepted or highest voted one).

This seems to work fairly well over on Arqade. It draws attention to posts in need of attention, and offers incentive to users to add new answers, or to update ones they've already posted. You can also include details in the bounty about why answers need to be updated now (e.g. a patch may have changed how something works in the game).

Not sure how well this would translate to a site the size of Stack Overflow, though.

  • 4
    roughly between 400 and 500 bounties are active on SO data.stackexchange.com/stackoverflow/query/1375188#graph and I don't think that is enough to address all stale answers ..
    – rene
    Commented Feb 18, 2021 at 17:18
  • 8
    Realistically, any project at scale on SO has to be broken into pieces; might do a "SQL Server outdated answers" campaign, but probably not a "SQL outdated answers" and definitely not a "everything all at once".
    – Shog9
    Commented Feb 18, 2021 at 17:23
  • 3
    The issue with this approach is, of course, that generally the new and updated answer will sit at the bottom of the list, with a handful of upvotes and an awarded bounty, while outdated answers may keep existing at the top with tens of upvotes and a green checkmark. Commented Feb 19, 2021 at 7:57

Adding this idea since it hasn’t been mentioned yet.

On Travel answers get outdated quite a lot of the time especially during the COVID-19 pandemic.

To combat this issue, the moderators have been adding the “This post relates to a rapidly changing event.” notices to posts relating to the COVID-19 pandemic which shows readers that the information may not be up-to-date. When the answer becomes out of date we usually leave a comment with the updated information for the author to edit in or if the author is inactive, post the updated information at the top of the answer saying that it was added by members of the community.


For software and programming questions on sites like the GIS Stack Exchange I recommend that ongoing curation of Q&As should try to steer answerers and editors towards trying to include the version(s) that an answer applies to.

That way, over time, the community can use:

  • upvotes to promote answers that are useful for the recent versions;
  • downvotes to demote answers that only apply to versions that few people are still using

The ordering of answers that results (excluding Accepted answers) will be:

  1. current and useful to many (expect displayed vote to be high positive)
  2. outdated and useful to only a few (expect displayed vote to be low positive)
  3. unlikely to be useful to anyone (expect displayed vote to be high negative, and a candidate for deletion)
  • 4
    I'm not sure this is a scalable solution. Versioning every single answer has at least two immediate problems: 1. we don't always get a "new" way of doing things. And the old ones tend to still be able. Do we need to revise all answers, say, once a year and say "works for <current year>"? This seems excessive. 2. New doesn't necessarily mean better. By demoting old content that suggests that it's "worse" when applicability might vary. It's possible that an old approach is the most widely applicable while newer one is for more specific cases.
    – VLAZ
    Commented Feb 19, 2021 at 7:59
  • @VLAZ there’s no suggestion of versioning every answer, it’s a direction to head rather than any sort of mandate.
    – PolyGeo
    Commented Feb 19, 2021 at 9:26
  • 1
    But what about 10 years in the future? If we do take that path, then we'd want more and more answers to be versioned. And all the existing versioned answers need to be continually revised to say they are still applicable or not. Even if we find in 2022 that an answer is no longer applicable for any change, in 2023 that might change again and the answer is valid once more.
    – VLAZ
    Commented Feb 19, 2021 at 10:14
  • @VLAZ Not every answer needs to have the version(s) it applies to included, but when one does that is additional information that voters can use to assess the ongoing usefulness of an answer.
    – PolyGeo
    Commented Feb 19, 2021 at 13:14
  • "downvotes to demote answers that only apply to versions that few people are still using" that's not very nice to contributors. Commented Mar 1, 2021 at 3:51
  • @FranckDernoncourt it’s not about the users, it’s about the post content. Answers that are only useful for versions that are rarely used nowadays are less useful today than those that are useful for versions in current use.
    – PolyGeo
    Commented Mar 1, 2021 at 4:29
  • 1
    @PolyGeo good post content comes from good contributors. Downvoting them does not help to keep them around. We should have a mechanism to handle different versions that doesn't involve downvoting. Commented Mar 1, 2021 at 4:31
  • @FranckDernoncourt upvotes outscore downvotes on answers by a factor of 5. Many good contributors will be maintaining their answers as new versions are released, but sometimes maintenance is triggered by a downvote that alerts them when their answer is becoming less useful. Improving answers should lead to them receiving upvotes. You may say that a comment would alert them, and that is true, but a comment is not single-click.
    – PolyGeo
    Commented Mar 1, 2021 at 4:41

Deletion votes are a 10k privilege on questions and 20k privilege on answers.

My question is how those privileges haven't been enough to solve the problem?

Most users like myself don't have 10k-20k, so I'm unable to grasp how the community didn't delete the problematic posts over time.

  • 14
    Most, if not all, outdated answers don't need to be deleted (at least not by someone other than the author). The linked Meta.SO post lists different kinds of "outdated answers". See also Nick's comment under said post. Also, check out the "When should I vote to delete an answer?" section of the 20k - Trusted User privilege.
    – 41686d6564
    Commented Feb 18, 2021 at 18:12
  • 3
    Another aspect here is that a lot of answers that are "outdated" in the sense that they were never great to begin with, also attracted a lot of upvotes by virtue of being visible longer. Deleting those is quite hard as you need hundreds of downvotes to flip the score and bring it down to delete range.
    – VLAZ
    Commented Feb 19, 2021 at 7:51
  • 3
    @VLAZ If the answer doesn’t have deeper problems (namely security problems), then you probably don’t need to delete it, just get it below the better answers. Still, not an easy task and impossible if the answer is accepted (much like deletion).
    – Laurel
    Commented Feb 19, 2021 at 14:21
  • 2
    @Laurel the post asked for why weren't problematic posts deleted. The first comment already mentioned that not all should be deleted. I tried to explain why some that should instead aren't because there is no feasible way to cover the requirements for deletion. Overall, the point is that deletion isn't a solution. There was a perhaps unintentional subtext that users with delete privilege are just not doing their jobs (enough). Yet that's not the case - sometimes users shouldn't delete stuff, sometimes users cannot delete stuff.
    – VLAZ
    Commented Feb 19, 2021 at 14:40

I'm pretty sure this does not easily translate to most other sites in the network, but IMHO it's still worth mentioning.

One way to deal with outdated answers is how Ask Ubuntu does it. This is the tag excerpt for [14.04], an old version of Ubuntu:

Fifth LTS (Long Term Support) release of Ubuntu, code-named "Trusty Tahr". Released on 17th April, 2014 and has reached its End Of Life (EOL) in April 2019. Questions specific to 14.04 are no longer supported here and are supposed to be closed as off-topic.

Of course, those five-year-old answers may not be outdated themselves, but it's basically a stance of 'most old content doesn't matter and it's not worth spending significant effort on it'.

  • 4
    Maybe they should belong on RetroComputing, along with all of SuperUser's XP questions :) Commented Feb 18, 2021 at 21:56
  • 2
    Tag versioning works as long as tags can be versioned meaningfully. Also, if the question falls within one tag. There are all sorts of possible combinations that will make versioning quite hard. That's not to say that we shouldn't do that, just that right now that's not a solution that can work everywhere. Having hierarchical tags where [foo-12] also implies [foo], for example, might help as it allows people to search for the master tag but doesn't take up precious tag space.
    – VLAZ
    Commented Feb 19, 2021 at 7:47

It would be great if an answer could be flagged by the answerer as a challenge of the already accepted answer making it possible for the community to vote for it as the new accepted answer.

Also, possibility of flagging a question as deprecated would be great.

  • Oh, and people who downvote answers without reason should have their profiles erased... Commented Aug 2, 2022 at 13:03

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