Over the lifetime of its sleep tracking line, Withings has released multiple hardware revisions, including the original Nokia Sleep, the Withings Sleep, and the medical-grade Withings Sleep Analyzer. Because firmware capabilities, apnea detection algorithms, and cable configurations vary significantly across these generations, identifying your exact model ensures you follow the correct troubleshooting path.
Quick Answer
Identify your Withings sleep mat by checking the printed label on the internal plastic module inside the fabric cover. The original Nokia/Withings Sleep carries model number WSM02, while the newer Withings Sleep Analyzer is designated WSM03. The WSM03 features an upgraded sound sensor for sleep apnea detection and uses a captive power cord.
The Evolution of the Withings Sleep Hardware
Withings has produced three primary versions of its under-mattress sleep tracking hardware:
[ Nokia Sleep (2018) ] ──> [ Withings Sleep (2019) ] ──> [ Withings Sleep Analyzer (Current) ]
Model: WSM02 Model: WSM02 (Rebranded) Model: WSM03
Modular Micro-USB Modular USB Cable Captive Reinforced USB
Basic Snoring Sound Sensor Added Medical-Grade Sleep Apnea (EU/FDA)
- Nokia Sleep (WSM02, 2018): Released during Nokia’s brief acquisition of Withings. Features Nokia branding on the cover and uses a modular, detachable Micro-USB cable.
- Withings Sleep (WSM02, 2019): Released after Withings became independent again. Carries the Withings logo, retains the WSM02 model number, and relies primarily on ballistocardiography with basic snore tracking.
- Withings Sleep Analyzer (WSM03, Current Generation): Features upgraded sensor hardware, including an internal acoustic sensor specifically calibrated to track medical-grade sleep apnea and breathing disturbances.
Physical and Technical Comparison Matrix
Use this comparison table to identify your hardware:
| Feature / Specification | Original Nokia Sleep | Withings Sleep | Withings Sleep Analyzer |
|---|---|---|---|
| Model Number on Label | WSM02 | WSM02 | WSM03 |
| Exterior Branding | “Nokia” stitched on tab | “Withings” stitched on tab | “Withings” stitched on tab |
| USB Cable Type | Detachable Micro-USB | Detachable USB-A to Micro-B | Captive / Hardwired USB-A |
| Cover Textile Color | Light Gray Melange | Slate Gray | Dark Charcoal / Heather Gray |
| Acoustic Sensor | Basic Snore Audio | Basic Snore Audio | Medical-Grade Sound Sensor |
| Sleep Apnea Classification | No (Disturbances only) | Breathing Disturbances only | Clinical Apnea Detection |
| Reset Switch Type | Recessed Pinhole | Recessed Pinhole | Recessed Pinhole with LED Ring |
How to Find the Model Number and Serial Information
The definitive way to confirm your hardware version is by reading the regulatory label on the plastic electronics module:
┌──────────────────────────────────────────────┐
│ Model: WSM03 [ Regulatory Marks ] │
│ S/N: 00:24:e4:xx:xx:xx FCC ID: XXXXX │
│ Input: 5V === 1A │
│ Made in China Withings │
└──────────────────────────────────────────────┘
Step 1: Open the Fabric Encasement
- Unplug the mat from wall power.
- Locate the zipper on the outer textile sleeve and unzip it 6 to 8 inches.
- Locate the black or dark gray plastic module attached to the internal air bladder.
Step 2: Read the Regulatory Print
- Look at the flat side or back of the plastic module.
- Find the line marked Model:
- If it reads WSM02, you have an original Nokia Sleep or early-generation Withings Sleep.
- If it reads WSM03, you have the current Withings Sleep Analyzer.
- Note your 12-character MAC address (format
00:24:e4:xx:xx:xx), which serves as the unique hardware identifier for your home network router.
Finding the Model in the Withings Mobile App
If your mat is already installed under a heavy mattress and currently connected to your network, you can identify the hardware without unzipping the cover:
- Open the Withings app on your phone.
- Tap the Devices tab at the bottom right.
- Select your sleep tracking mat.
- Scroll down and tap Technical Information:
- Model: Displays either Sleep (WSM02) or Sleep Analyzer (WSM03).
- Firmware Version: Displays your current operating build (e.g., 2001 or higher).
- Serial Number: Matches the physical MAC address on the internal module.
Why the Generation Difference Matters for Troubleshooting
Knowing your specific model prevents misdiagnosis and helps resolve issues faster:
- Power Supply Replacement: If you damage the cord on a WSM02, you can replace it with any standard off-the-shelf USB cable. If you damage the cord on a WSM03, the cable is hardwired into the enclosure and must be spliced using the steps in Frayed USB Cable? How to Replace Your Withings Power Cord.
- Feature Availability: If your app does not show clinical Sleep Apnea severity metrics, verify whether you have a WSM02. The older WSM02 model lacks the dedicated acoustic hardware required for clinical apnea tracking and only records general breathing disturbances.
- Pump and Bladder Parts: Replacement air bladders, pump valves, and internal line barbs differ between the WSM02 and WSM03 revisions. Knowing your model ensures you use the correct parts when completing pneumatic repairs like Withings Leak? How to Repair a Punctured Sleep Air Bag.