GitHub Copilot's Market Share Fell From 67% to 51%. Reliability Did It.

A year ago, GitHub Copilot was the default. Two out of three professional developers used it. That number is now barely half.

CNBC reports that Copilot's share among professional developers dropped from 67% in 2025 to 51% in 2026. Cursor jumped to 29%. Amazon Q Developer grabbed 14%. The decline lines up with two ugly outages: a May 7 database migration failure that took Copilot offline, and a May 15 Actions degradation where 42% of runs were failing at peak.

GitHub's VP of Engineering said they "have not met our own high bar for service availability." The response: a dedicated reliability team, a week-long development freeze, and a promise to publish per-component health metrics. That's the kind of announcement you make when the board is asking questions.

I've been watching this fragmentation happen in real time. Six months ago, recommending anything other than Copilot for a team felt contrarian. Now it feels obvious. Cursor's agent mode, Amazon Q's AWS integration, and the growing local model stack (more on that in story #2) all offer something Copilot doesn't: the confidence that it'll be there when you need it.

This tracks with a Gartner report from May 20 that sizes the enterprise AI coding agent market at $9.8-11 billion and predicts over 65% of engineering teams will treat IDEs as optional by 2027. The whole category is reshuffling. Vendors are moving from seat-based to usage-based pricing. The moat isn't features anymore. It's uptime.

What should you do? If you're on Copilot and haven't tried alternatives, now's the time. Not because Copilot is bad. Because you need a fallback. I run Claude Code in my personal projects every day, and the fact that I don't depend on a single tool is exactly why outages don't wreck my workflow. Diversify your AI coding stack the same way you'd diversify any critical dependency.