Internet Explorer's 25-Year Run Finally Ends

Today’s the day. Microsoft has officially ended support for Internet Explorer 11 across most Microsoft 365 apps and services, and while the browser technically isn’t being deleted from your PC just yet, this is the functional end of the line. If you’re still opening IE out of habit, expect more and more of the modern web to start looking broken, or to just tell you to go install Edge instead.

It’s hard to overstate how dominant Internet Explorer once was. It shipped back in 1995, bundled into Windows, and by the early 2000s it had swallowed something like 90%+ of the browser market. For a huge chunk of people, IE simply was the internet. There was no meaningful alternative in most households or offices.

That dominance is exactly what made it so stagnant. Once Microsoft had effectively won the first browser war, development slowed to a crawl. Standards support lagged, security holes piled up, and “works best in Internet Explorer” became a punchline rather than a badge of honor. Firefox chipped away at it in the mid-2000s, and then Chrome came in and finished the job over the following decade. By the time Edge launched in 2015, IE was already a legacy product being kept alive mostly by inertia and enterprise contracts.

And that’s really the story of today’s cutoff. This isn’t really about consumers — most regular users left IE behind years ago. This is about the enterprise IT departments that never had a good reason to move on. Anyone who has worked adjacent to a large company’s internal tools knows the pattern: some critical intranet app or vendor portal was built in the early 2000s, it only works properly in IE’s compatibility mode, and nobody wants to touch it because touching it means someone has to actually rebuild it. Those teams are now staring down a real scramble, either standing up IE mode inside the new Chromium-based Edge or biting the bullet on rewriting decades-old internal software.

There’s something fitting about the timing too. Edge itself moved to a Chromium base a couple of years back, essentially conceding that the rendering engine wars are over and Blink (or WebKit, if you count Safari) won. IE mode in Edge will keep the zombie alive for enterprises that truly can’t migrate overnight, but it’s a bridge, not a destination.

For younger developers who never had to write triple-nested conditional comments just to get a layout to render correctly in IE6, this whole saga probably sounds like ancient history. For the rest of us, it’s hard not to feel a little bit of relief mixed with nostalgia. Two and a half decades is a long time for any piece of software to stick around, especially one that spent its last ten years being actively despised by the same web developers who once had no choice but to build for it.

The lesson here isn’t really about browsers specifically — it’s about what happens to any product that wins so completely it stops needing to improve. IE’s fall from 90% market share to irrelevance is one of the cleaner case studies in tech of what complacency costs you, even when you start from a position that looks unassailable.