OpenAI Plans to Launch GPT-5.6 and Major Codex Updates as Microsoft Build Conference Kicks Off
Alina Collins
OpenAI and Microsoft are launching AI products in the same week — OpenAI unveils GPT-5.6 and a major Codex upgrade while Microsoft opens Build 2026 with its own reasoning model, putting the two giants in a head-on contest for the developer ecosystem.
How good is GPT-5.6 — and how much does it cost?
Sources say GPT-5.6 brings major improvements in reasoning, front-end generation, personalization, and agentic workflows, targeting a 12%–15% gain over GPT-5.5.
Pricing sits at roughly one-third to one-half of Anthropic's comparable model, with similar performance. This means → OpenAI is bidding for enterprise customers with a "match the capability, halve the price" play.
One insider said GPT-5.6 "could easily have been called GPT-6." In plain terms = the upgrade is large enough to qualify as a new generation; OpenAI simply chose not to rename it.
All of the above comes from unofficial channels; OpenAI has not formally confirmed it. Polymarket puts the probability of a public release by end of June at roughly 80%–89%.
What does the Codex upgrade mean?
The Codex team spent months evolving Codex from a "code-completion tool" into a full "coding agent."
This means → Codex no longer just writes the next line of code — it can take over longer, more complex programming workflows, faster and cheaper.
OpenAI has already confirmed that Codex and its frontier models are fully available on AWS Bedrock. This reflects OpenAI actively embracing multi-cloud deployment rather than staying locked to Microsoft Azure alone.
What is Microsoft showing at Build?
Per The Verge, Microsoft will release its first in-house reasoning model, MAI-Thinking-1; AI chief Mustafa Suleyman had previously previewed the image-generation model MAI-Image-2.5.
Per The Information, Microsoft also plans a coding model to sharpen GitHub Copilot's edge. This means → Microsoft is no longer just distributing OpenAI's models — it is filling gaps with its own.
Microsoft is also expected to show the first Windows PCs running custom Nvidia AI chips and to ship a developer-focused Windows 11 experience.
How far along is Microsoft's "super app"?
Microsoft is building an app that merges GitHub Copilot, Copilot Chat, collaboration tools, and an agentic-workflow feature internally code-named "Autopilot."
In plain terms = every AI coding and collaboration feature goes into one entry point, so developers stop jumping between tools.
But per Fortune, the super app is not expected to ship at this Build conference.
Who leads in coding benchmarks — and what does the competitive picture look like?
AGI Ranker's latest data: Anthropic's Claude Opus 4.8 tops the coding leaderboard at 81.01, while OpenAI's GPT-5.5 scores 77.48 — a 3.5-point gap.
Anthropic has confidentially filed an S-1 IPO prospectus with the SEC. This reflects the top AI companies accelerating on both the technology and capital fronts simultaneously.
This means → OpenAI's push for GPT-5.6 and Microsoft's in-house models are both competitive responses to Anthropic's technical lead and impending public listing.
Content is for reference only, not financial advice.