The number of questions on Stack Overflow fell by 78 percent in December 2025 compared to a year earlier. Developers are switching en masse to AI tools in their IDEs, making the popular developer forum increasingly irrelevant.
In December 2025, only 3,862 questions were asked on Stack Overflow. That is a total implosion compared to the platform in early 2014, when more than 200,000 questions were posted per month. The shift is clear: developers now use AI assistants such as GitHub Copilot directly in their IDE, bypassing the forum. That was also the conclusion when we looked at the decline of Stack Overflow last year, but this trend is continuing.
According to a Stack Overflow survey from 2025, 84 percent of developers now use or plan to use AI tools, up from 76 percent a year earlier. This rapid adoption partly explains the decline in forum activity.
Toxic moderation plays a role
However, AI is not the only culprit. Many users point to hostile treatment by moderators, explains DevClass. Stack Overflow focuses on a limited number of “high-quality” questions, but that policy makes it difficult to attract new users.
Nevertheless, Stack Overflow emphasizes that the number of questions is not a good measure. But the fact that participation in the community seems to be discouraged does suggest that a decline is inevitable. Reddit, which as an online forum does not focus on specific issues, does not have such an attitude. It stands to reason that users who do not want to use AI for their coding help can get assistance on that platform, for example.
Impact on programming language data
The decline has consequences for data analysis in any case. The Redmonk Language ranking for programming languages uses Stack Overflow for half of its data, with the other half coming from GitHub. Incidentally, measuring the popularity of languages, such as via the TIOBE Index, is questionable. We simply do not get a true representation of the relative proportions, as much of the code is locked away in closed-source projects.