Xiaomi's HyperOS 4: A Measured UI With an Ambitious AI Core

First Impressions: A Restrained Facade, an Ambitious Inside

Xiaomi has always moved fast—fast product cycles, fast price adjustments. But when it came to AI, they took their sweet time. Apple's big AI announcement has already slipped two years, and even Doubao has a second-gen phone. Now, with HyperOS 4, Xiaomi finally ships its first AIOS.

After spending a few weeks with a Xiaomi 17 Ultra running the new software, I'm struck by a strange mix. On one hand, AI has been woven into nearly every corner of the OS. On the other, I can't help but want more from how it fits into Xiaomi's broader ecosystem. As a first attempt, it's a solid one.

Design: Clean Glass, Not Overdone

The visible changes are few but refined. HyperOS 4 introduces a glass-like aesthetic—lock screen, control center, and folders get a translucent, layered look. Dragging an icon or toggling a switch shifts the light and shadow around it. The lock screen clock can be resized and repositioned, notifications stack neatly when they pile up, folders stretch to different sizes, and widgets can stack on top of each other.

Xiaomi didn't go overboard with the glass effect. The interface stays clean, text and controls remain legible. It's a welcome return to a more mainstream design language.

Performance-wise, the update brings better load balancing, memory preloading, and app management. In daily use, that translates to fewer stutters and noticeably better battery life.

AI Everywhere: Super Xiao Ai Takes Over

The real story is behind the scenes. AI has been injected into the system's very foundation. Super Xiao Ai, the upgraded assistant, is no longer just a chat buddy—it's a system orchestrator, handling memory, input, and cross-app actions.

Back in July, Xiaomi split Xiao Ai (which has over 100 million monthly active users) into three parts: model infrastructure, cloud engineering, and on-device products. The base model lives with the MiMo team, while product capabilities are handed to individual device business lines. This shift signals something big: AI is no longer a single department's product—it's becoming company-wide infrastructure.

Memory That Works

One of the most impressive features is Xiao Ai Memory. With a three-finger swipe up on any screen, the system recognizes and stores what's on screen into Super Xiao Ai's memory. Later, you can just describe what you saw, and it resurfaces. Recognition is accurate, and retrieval is fast.

But memory is still mostly about recording and answering. For example, if you save a food pickup receipt, I'd love it to automatically extract calories or log the expense—not just tell me what it is. The company says features like bringing pickup codes to the Dynamic Island will arrive via OTA by the end of August, so there's hope.

Memory also syncs across devices. Phone memories, conversations, notes, and photos can be accessed on a PC via Xiaomi's inter-connectivity app, and vice versa. Super Xiao Ai now works on Windows and Mac too, not just within Xiaomi's own ecosystem.

Automation and Smart Home

Scheduled tasks handle repetitive chores—like checking email or refreshing your calendar at the same time every day. I tested several of these, and they rarely failed. And if you have Xiaomi smart home gear, you can give a command like, “I'll be home in an hour and want to watch a movie,” and the AI will break it down: turn on the AC, close the curtains, adjust the mood lighting, and queue up the film on the TV.

Notably, there's now a paid AI subscription tier. Xiaomi is clearly exploring how to use AI services to add value to hardware. Users get 1,000 free credits per month—enough for roughly 50–80 expert-mode conversations (each costs about 12–20 credits). Heavier tasks like generating a PDF or PPT cost 100–300 credits each.

Pricing tiers are: 29 RMB/month (or 19 with a yearly plan) for 4,000 credits; 59 RMB (39 discounted) for 10,000; and 149 RMB (99 discounted) for 34,000.

AI in Native Apps

Many built-in apps have gotten AI upgrades. The Notes app is the most changed. It now supports live recording that identifies different speakers, then automatically generates a transcript and meeting summary. You can edit further and export. That's a huge time-saver for meetings or quick idea capture.

The Recorder app also got AI features like real-time subtitles and auto summaries. Interestingly, both apps use the same MiMo-V2.5 model, but their data isn't fully integrated yet. That's a recurring theme in HyperOS 4: AI is everywhere, but memory isn't fully unified. I suspect Xiaomi will fix that in future updates.

Super Xiao Ai Input Method is another example. Beyond standard AI help—rewriting, generating, answering—it adds AI voice input. When you talk, words appear in real time, and when you pause, the content is cleaned up into tidy, readable text. You can edit it further or translate it. Voice input is arguably faster than typing in the AI era, and this implementation is already quite usable.

Interaction: Smart Island and Future Tricks

For longer agent tasks, HyperOS 4 shows progress on the “Super Island” (Xiaomi's version of the Dynamic Island), so you always know what's happening. Global AI writing help and memory features are handy too. But the Xiaomi 17 Ultra doesn't have a dedicated AI button—features like memory and voice input aren't as intuitive to trigger by feel. I hope the 18 series adds one.

One feature I'm eager to try is “Inspiration Ball,” which hasn't launched yet. It's a global magnifying glass: you park it over any part of the screen, summon Xiao Ai, and it searches or answers about that specific content. That's a clever way to give the AI precise context without describing which screen something is on. It complements memory perfectly—one stores info, the other fetches it precisely.

Why This Matters: AI as the Foundation

Look at the three threads—memory, apps, interaction—and it's clear Xiaomi isn't just bolting AI onto an old OS. AI is becoming the base layer, both for the system and the ecosystem. Few device makers have this kind of reach.

Xiaomi holds a rare combination: its own foundation models, its own OS, and a sprawling consumer ecosystem (phones, PCs, smart home, even cars). That vertical integration means AI can touch system-level data and permissions directly, not just via app-layer APIs. And with seamless cross-device connectivity, context flows—what you remember on your phone is ready on your PC, and your habits inform your smart home.

While competitors debate which model to integrate, Xiaomi has already embedded its model into the system. Having the full pipeline gives them a better chance of not being “eaten” by AI. But there's risk too: the tighter the model is coupled to the system, the smarter it must be. If the base model underperforms, errors—bad memories, failed tasks—become system-wide problems.

Lei Jun has committed 60 billion RMB to AI over three years. In today's AI funding climate, that's not a king's ransom, but it's enough to put up a fight. For Xiaomi, the challenge is huge, but so is the opportunity.

Clearly, “AI+” is replacing “Internet+” as the company's core narrative. As the slogan goes, “Only Xiaomi's AI can make an AI Xiaomi.” HyperOS 4 shows the strategy is in place. The open question remains: how smart can the underlying model get? The real AI phone era is about to begin, and Xiaomi has its cards on the table. How they play them is a matter of tactics—and time.