The company's developer conference opens in San Francisco with another round of AI tooling expected, against the awkward backdrop of how few people pay for Copilot.

Microsoft opened its annual Build developer conference in San Francisco on Tuesday, with Satya Nadella due to take the stage at 9:30am Pacific for a keynote that, by every signal the company has sent, will be about putting artificial intelligence into as many corners of its products as it can.

The conference runs June 2 and 3, in person and online, and is pitched squarely at the developers Microsoft needs to build on top of its platforms.

The broad direction is not in doubt. Microsoft has spent the past year reframing Windows as a host for AI tools and agents rather than a passive operating system, and Build is where it courts the developers who would write for that vision.

Reporting ahead of the event, including from Reuters, pointed to new PC-side and cloud AI tooling as the centrepiece, the latest instalment in a strategy Nadella has pursued relentlessly since the company's OpenAI partnership began.

The specifics of what was unveiled on stage should be read against the official Microsoft announcements rather than the preview chatter, which this year has been unusually heavy on speculation.

What gives the event its tension is not the technology but the take-up. On its most recent earnings call, in late January, Microsoft said it had 15 million paid seats of Microsoft 365 Copilot. That is a striking number until it is set against the 450 million commercial Microsoft 365 seats the company also reported, at which point it becomes a conversion rate of roughly 3.3%.

Nadella told investors that Copilot was “becoming a true daily habit,” citing daily active users up tenfold year on year, but the gap between people who can use Copilot and people who pay for it remains the most stubborn fact in Microsoft's AI story.

The company has been acting on that gap in ways that complicate the upbeat keynote framing. Earlier this year it began letting users and administrators uninstall Copilot from Windows 11 outright, a concession to the many who never wanted it bundled in. At the same time it has been building out its own MAI model family, a move widely read as an effort to depend less on OpenAI for the intelligence under Copilot's hood.

So Build arrives as both a showcase and a sales pitch. Microsoft has the distribution, the cloud, and the developer base that almost no rival can match, and it has a product millions of people have access to and decline to buy. The keynote will be heavy on what AI can now do inside Windows and Azure.

Whether developers, and the customers behind them, decide it is worth paying for is the question the announcements are really meant to answer. The conference will say what Microsoft is building. It will not, by itself, settle who is buying.