Xiaomi's HyperOS 4: A Free Living AIOS That Finally Feels Like It

The Wait Is Over

For years, Xiaomi phones were known for speed—fast iteration, fast price cuts—but when it came to AI, the company moved at its own leisurely pace. While the rest of the industry raced ahead with AI narratives, and Apple's grand AI plans kept slipping, Xiaomi quietly bided its time. Now, with HyperOS 4, the company has finally shipped its first AIOS, and I've been living with it on a Xiaomi 17 Ultra for a while. The experience is a mix of surprise and anticipation.

Design: Restraint on the Surface

The visible changes are subtle but refined. HyperOS 4 adopts a glassy aesthetic—lockscreen, control center, and folders get a translucent, layered look. Icons and toggles respond to touch with subtle light shifts. The lockscreen clock can be resized and repositioned, notifications stack neatly, folders stretch to different sizes, and widgets pile up. It's clean, legible, and finally on par with mainstream design trends.

Performance is smoother too, with optimizations in load balancing, memory preloading, and app launching. In daily use, stutters are rare, and battery life has improved noticeably. The understated UI masks the real revolution happening underneath.

AI Everywhere: The Invisible Overhaul

HyperOS 4 is not just an OS with AI features bolted on; it's an OS where AI is the foundation. The centerpiece is Super Xiao Ai, which has evolved from a simple voice assistant into a system-wide controller handling memory, input, and cross-app actions. Xiaomi split Xiao Ai into three modules last July: model infrastructure, cloud engineering, and on-device products. The base model now belongs to the MiMo team, while product capabilities are distributed across business units. AI is no longer a single product—it's the company's backbone.

Memory: The Global Recall

One of the standout features is Xiao Ai's global memory. Swipe up with three fingers on any screen, and the system captures it into memory. Later, you can just describe what you saw, and it'll pull it up. The recognition is impressive, and retrieval is seamless. But it's still limited to recording and answering—it can't yet act on the content. For instance, if I capture a food pickup receipt, I'd love it to automatically extract calories or log an expense, but right now it just tells me what it is. There's hope: Xiaomi says live activities for pickup codes and queue numbers are coming via OTA at the end of August.

Memory syncs across devices too. Phone memories, conversations, notes, and photos flow to the Xiaomi Interconnect app on PC, and you can search and pull files from your PC on your phone. Even Windows and Mac are supported now.

Automation and Smart Home

Scheduled tasks handle repetitive chores—like checking email or refreshing your calendar at set times. I've tested these, and they've been reliable. And the smart home integration is where it gets fun. Tell Xiao Ai, "I'll be home in an hour and want to watch a movie," and it'll parse the intent, turn on the AC, draw the curtains, set the mood lighting, and queue up your film—all before you walk in.

Monetizing AI: The Subscription Model

HyperOS 4 also introduces an AI subscription service. Using 'Expert Mode' for tasks consumes points, but you get 1,000 free points monthly. According to Xiaomi, a typical conversation costs 12–20 points, so that's 50–80 free uses a month. Heavier tasks like PDF or PPT generation run 100–300 points. Paid tiers start at 29 RMB/month (19 RMB with continuous subscription) for 4,000 points, go up to 59 RMB (39) for 10,000, and top out at 149 RMB (99) for 34,000. It's a clear attempt to add value to hardware through AI services.

Apps Reimagined

Notes have gotten the biggest AI upgrade. You can record audio in real time, with speaker diarization, and it spits out a transcript and meeting summary, ready for further editing or export. It's perfect for meetings or capturing ideas on the fly. The Recorder app also supports live captions and AI summaries. Interestingly, both apps use the same underlying MiMo-V2.5 model, but their data isn't fully integrated yet—a sign that while AI is deep, the memory layer isn't fully connected. I expect Xiaomi will fix that in future updates.

The Super Xiao Ai keyboard is another example. Beyond standard AI assist, it nails voice input. Speak, and words appear in real time; pause, and it organizes your speech into clean text, with options for editing or translation. Voice is faster than typing, and this implementation is solid.

These AI touches are everywhere—I keep discovering them in unexpected corners of the OS. That's exactly the kind of pervasive integration I appreciate.

Interactions: Making AI Feel Natural

For longer agent tasks, HyperOS 4 shows progress in the Super Island, so you always know what's happening. Global AI writing and memory are handy, but the Xiaomi 17 Ultra lacks a dedicated AI button—you have to fumble for gestures. A physical key on the Xiaomi 18 would be a big improvement.

There's also an upcoming feature called 'Inspiration Ball' that I'm excited about. It's a global magnifier you can park anywhere on the screen, then summon Xiao Ai to search or answer about that specific area. It gives the AI precise context—no need to describe where something is; just point at it. That's smarter than describing, and it complements memory perfectly: one stores, the other retrieves.

The Bigger Picture: An AI-First Ecosystem

HyperOS 4 isn't about adding AI features; it's about making AI the operating system. Xiaomi is one of the few companies with the full stack—its own models, its own OS, and a sprawling device ecosystem. That vertical integration means AI can reach deep into system data, not just bolt on via apps. Cross-device context flows: what your phone remembers, your PC can use; your habits inform your smart home.

But there's a catch. The tighter the coupling, the smarter the model needs to be. If the base model lags, errors become system-wide. Xiaomi has pledged 600 billion yuan over three years for AI—a lot, but not lavish by industry standards. It's a huge challenge, but also a massive opportunity.

As Lei Jun said, 'Only Xiaomi's AI can make AI Xiaomi.' HyperOS 4 shows the strategy is clear. The real question now is: how smart can the models get? The AI phone era is just beginning, and Xiaomi has its cards on the table. How it plays them is a matter of tactics and time.