Developers said 72% block ads. Counting actual visits gave 32%.
398 words · about 2 min
The widely-quoted figure that 72.3% of developers run ad blockers comes from asking them. The one measurement of the same group taken at the same time by counting real visits found 32% — people said it 2.3 times more often than they did it.
- How it was measured
- We traced the 72.3% back to the raw spreadsheet of Stack Overflow's 2018 survey results; it is not on the published report page at all. We then compared it against Read the Docs' own count of its visitors from the same year, and then against four separate measurements in other subject areas.
- Last checked
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If you have read anything about making money from an audience of programmers, you have met the figure: 72.3% of developers run ad blockers. It gets used to argue that a site for developers cannot be funded by advertising.
It comes from Stack Overflow's 2018 survey of developers. Two things about it are worth knowing.
First, it is not in the published report. Neither 72.3% nor the statistic that goes with it appears on the 2018 results page. Both exist only in the raw spreadsheet behind it. Anyone citing "the Stack Overflow survey says" from the report is citing something that is not there.
Second, it comes from asking people. Read the Docs serves documentation to the same kind of audience. In the same year it counted how many of its own visitors were actually blocking ads — not asked them, counted them — and published the answer: "32% of Read the Docs visitors run an ad blocker."
That is a 2.3-times gap between what developers say and what they do, and it explains why the survey figure has never turned up anywhere else.
Every count since lands in the lower band
Mediavine's technology and computing category: 10–30%. Publisher Collective: 32%. NitroPay: 25%. 9GAG: 33%.
Counted ad-blocking among technical audiences sits at 25–33% — at or below the 33% that eyeo, which makes Adblock Plus, reports for the US population as a whole in 2026.
The figure cannot be brought up to date
Stack Overflow asked once, in 2018, and never again — we checked the 2019, 2024 and 2025 surveys one by one. Blockthrough's public series stopped in 2023. eyeo's 2026 report groups people by type rather than by job, and its own description of the method says the data by subject area was gathered and simply not published.
So there is no current figure for developers anywhere. That is not "we could not find it" — it does not exist.
Reading eyeo's audience types
eyeo sorts people into types, and those are increasingly quoted. One number in them is routinely misread. "Tech suspicious 2.04" does not mean 2.04% of anything. It is a comparison figure from the research firm GWI, and it means people in that group are 2.04 times as likely to fall into that segment as the average person. Turning it into a percentage produces a number that does not exist.
Tracked as ADBLOCK-MEASURED-32, ADBLOCK-UNKNOWN. If a number here looks wrong, tell us and we will check it against the source.