OpenAI just officially put September 29 on the calendar, and the developer community is already buzzing. The company announced OpenAI DevDay 2026 this week, confirming that its annual developer conference is returning to San Francisco for what it’s calling its “biggest event of the year.” Registration details haven’t dropped yet, but OpenAI has already opened a notification sign-up page for developers eager to grab a spot.

For anyone who’s been following the company’s trajectory over the past few years, this announcement lands at a fascinating moment. OpenAI has grown from a research lab with a single chatbot product into something far more sprawling – a company building AI models, a browser, a social media app, and an AI-powered hardware device, all at the same time. The DevDay conference has become the one moment every year where all of that ambition gets distilled into a single stage presentation aimed squarely at the people who actually build with OpenAI’s tools.

It all started back on November 6, 2023, when OpenAI held its very first DevDay – and it was an event few people saw coming with the level of substance it delivered. The company announced new AI models, fresh APIs, doubled the token-per-minute rate limit for GPT-4 paying customers, and even launched Whisper large v3, an updated version of its open-source speech recognition model. It was a clear signal that OpenAI wasn’t just a consumer chatbot company anymore – it was gunning for the developer ecosystem in a serious way.

The 2024 edition dialed things back slightly in terms of spectacle, but was still meaningful for builders. OpenAI used that year’s event to roll out developer upgrades that mattered in practice, including a new API for AI voice capabilities – a feature that would quietly power a wave of new voice-enabled applications across the industry. It was the kind of announcement that doesn’t generate as many headlines as a shiny new model, but ends up mattering far more to the folks writing code every day.

Then came DevDay 2025, and OpenAI clearly decided it was done being understated. The company hosted the event on October 6, 2025, at Fort Mason in San Francisco, drawing more than 1,500 developers to what it described as its “biggest event yet.” The headliner pairing alone set the internet on fire – CEO Sam Altman shared the stage in a fireside chat with Jony Ive, the legendary Apple designer who spent decades shaping how we think about hardware and product design, and who has since been working with OpenAI on its AI device ambitions. The keynote opened with Altman unveiling “announcements, live demos, and a vision of how developers are reshaping the future with AI.“

The announcements at DevDay 2025 were substantial. OpenAI introduced apps directly inside ChatGPT, giving developers a way to build experiences that live within the chat interface itself. AgentKit made its debut – a tool designed to help developers build AI agents without needing to write heavy amounts of underlying code, dramatically lowering the bar for agentic app development. Sora 2 was folded into the API, meaning developers could finally start generating video programmatically, complete with what Altman described as immersive soundscapes and ambient audio effects synchronized to visuals. Codex got updates too, including integration with Slack and a new Codex SDK, and GPT-5 Pro launched in the API with detailed pricing tiers.

Now, heading into 2026, the stakes feel even higher. OpenAI has been on an absolute product blitz – the company’s model lineup now includes GPT-5.5, GPT-5.4, GPT-5.3 Instant, and GPT-5.3-Codex, all of which have landed in relatively rapid succession. The pace of release alone tells you something about where the company is right now: it’s shipping at a cadence that would have seemed improbable even two years ago. DevDay 2026 will almost certainly be the venue where OpenAI contextualizes all of that for developers – what’s available in the API, how pricing works, what the roadmap looks like, and what new tools are coming to help builders keep up.

One small detail in the announcement is worth paying attention to. OpenAI posted on X (formerly Twitter) that it will be selecting developers each week to win free tickets to DevDay 2026 – specifically by building something worth noticing. It’s a clever move that does double duty: it generates community buzz ahead of the event while also encouraging developers to actively ship projects using OpenAI’s tools in the months leading up to September. It’s the kind of grassroots hype-building that tech companies rarely do this well.

The location staying in San Francisco is no accident either. The city has reclaimed its status as the gravitational center of the AI industry over the past two years, with OpenAI, Anthropic, and a wave of AI startups all operating in and around the Bay Area. Hosting DevDay there isn’t just logistically convenient – it’s a statement about where the action is, and who the audience is. These are the engineers, founders, and researchers who wake up every morning thinking about what’s next, and OpenAI wants them in the same room, all at once, on September 29.

Registration details are still forthcoming, but OpenAI has confirmed that those who sign up on the DevDay 2026 page will be first to know when applications open. Given how fast the 2025 edition sold out and how much attention the company commands heading into the back half of 2026, it’s reasonable to expect demand for seats will be fierce. Whether you’re a solo developer building on the API or part of a larger team integrating OpenAI into enterprise products, this is shaping up to be one of the most important dates on the tech calendar this fall.