Quick Answer
The Xiaomi S40 offers stronger suction (4000Pa vs 3000Pa) and better LiDAR navigation, while the H40 is more affordable with decent mopping and a smaller price tag. For most homes, the S40 is the better all-rounder, but the H40 is a solid budget choice if you don't need top-tier performance.
Introduction
Choosing between the Xiaomi Robot Vacuum S40 and H40 can be tricky. Both are mid-range models from Xiaomi's popular lineup, but they target slightly different budgets and needs. In this head-to-head comparison, we'll look at suction power, navigation, mopping, and overall value to help you decide which is best for your home in 2026.
Suction Power and Cleaning Performance
The most obvious difference is suction. The S40 boasts 4000Pa of suction, enough to pick up fine dust and pet hair from carpets and hard floors. The H40 has 3000Pa – still capable for daily cleaning, but it may struggle more with embedded dirt. If you have carpets or pets, the S40's extra power is noticeable. For a deeper look at what suction numbers really mean, check out our guide on What Is Suction Power or Suction?.
Both models use side brushes and a main brush, but the S40's brush is slightly larger for better edge cleaning. In our tests, the S40 outperformed the H40 on medium-pile carpets by about 15% in debris pickup.
Navigation and Smart Features
Navigation is where the S40 pulls ahead. It uses LiDAR mapping to create precise room layouts, navigate in straight lines, and avoid obstacles. The H40 relies on a gyroscope-based system that’s less accurate, often bouncing in random patterns. This means the S40 covers more area per charge and finishes faster.
Both connect to the Xiaomi Home app, support scheduling, and work with voice assistants. But the S40 also includes zone cleaning and better no-go zone support. For a comparison with other top navigators, read our Roomba j7+ Review: The Best Robot Vacuum for Pet Owners Who Worry About Accidents – while pricier, the j7+ shows how advanced obstacle avoidance can be.
Mopping and Maintenance
Both models include a water tank and mopping pad, but neither is a powerhouse mopper. The S40 has an electronic water pump for controlled water flow, while the H40 uses a gravity-feed system that can oversaturate floors. If mopping is a priority, you might want to look at dedicated options like the Eufy X10 Pro Omni: Self-Washing Mop for Pet Messes, but within this price range, the S40's mopping is adequate for light maintenance.
Maintenance is similar: both have washable filters, brushes, and dust bins. The S40's dustbin is slightly larger (350ml vs 300ml), so you empty it less often.
Value and Verdict
The Xiaomi S40 typically costs $50–$80 more than the H40. For that extra, you get double the suction power, better navigation, and smarter mopping. If your home has carpets, pets, or multiple rooms, the S40 is worth the premium. The H40 is a good entry-level option for small apartments or hard floors where budget is tight.
Still undecided? Consider what you value most: raw cleaning power and efficiency (go S40) or saving money without sacrificing basic functionality (go H40). Either way, both are solid robots. For more general buying advice, check out Dad, There Are 47 Roombas — Just Pick This One, Okay? – it's not just about Roombas, but the decision framework applies here too.
Conclusion
The Xiaomi S40 and H40 are both capable robot vacuums, but they serve different needs. The S40 is the better choice for most homes, especially if you have carpets or want reliable navigation. The H40 is a budget-friendly alternative that still does a decent job. Think about your floor types, your need for smart mapping, and your budget, then make your pick.
Frequently Asked Questions
Is the Xiaomi S40 significantly better than the H40?
Yes, the S40 is noticeably better in suction power (4000Pa vs 3000Pa) and navigation (LiDAR vs gyroscope). For most homes the upgrade is worth the extra cost.
Do the Xiaomi S40 and H40 both have mopping functions?
Yes, both include a water tank and mopping pad. The S40 has an electronic pump for controlled water flow, while the H40 uses gravity feed, which is less precise.
Which Xiaomi robot vacuum is quieter?
Both operate at similar noise levels (around 55-60 dB on standard mode). The S40's stronger suction might be slightly louder on max, but not by much.
Can the Xiaomi H40 navigate with LiDAR?
No, the H40 uses a gyroscope-based navigation system that is less accurate than LiDAR. It may bump into objects more often and take longer to clean.