Microsoft's future browsers will not enable Do Not Track as the default setting, in a reversal of the company's policy with Internet Explorer 10
An update on Microsoft's approach to Do Not Track — As industry standards evolve, how we implement those standards evolve as well.
Context & Ripple Effects
When Microsoft shipped Internet Explorer 10 with Do Not Track enabled out of the box, it made the single most consequential default in online advertising — a signal most ad networks simply declined to honor. This reversal concedes that the experiment failed: a default nobody respects is noise, and Microsoft now frames its position as following evolving standards rather than leading them.
The arc closes nine years later, when Mozilla removed Do Not Track from Firefox entirely, making Firefox the first major browser both to add and then delete the flag because too few websites honored it. In between, Microsoft learned twice more that browser defaults are politically loaded — it backtracked on Windows 11's controversial default-browser changes after user pushback, and later agreed under the EU's Digital Markets Act to stop prompting EEA users to set Edge as their default browser.
First-order effects
- Ad networks, analytics providers, and publishers stop contending with a blanket do-not-track signal from the world's largest desktop browser base; only users who deliberately switch the flag on will send it.
Second-order effects
- Privacy advocates lose their flagship default-setting lever and shift pressure toward enforceable mechanisms — regulation and consent flows — rather than honor-system headers, accelerating the search for a standard websites actually obey.
Third-order effects
- Browser defaults are established as regulated territory rather than pure product choice: the DNT reversal, the Windows 11 default-browser climbdown, and the DMA's constraints on Edge prompts all point to vendors losing unilateral control over what ships switched on.
The trend: Browser privacy behavior is moving from unilateral vendor-set defaults like Do Not Track toward opt-in controls and regulator-mandated choice screens, as honor-based preference signals prove unenforceable.