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Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minuteTo identify your Apple Watch, find its five-digit hardware model number beginning with A, then match it with Apple’s official model list. You can reveal it in the Apple Watch app on a paired iPhone or find it in the watch’s Settings app.
Do not confuse the A-number with the part number beginning with M, the serial number, or the IMEI; each serves a different purpose.
Identify your Apple Watch with the paired iPhone
If the watch is paired with an iPhone, this is usually the easiest method:
- Open the Apple Watch app on the iPhone.
- Tap My Watch.
- Go to General > About.
- Find Model Number. It initially begins with M.
- Tap the Model Number field once. It changes to a five-digit number beginning with A, such as A2986.
- Compare that A-number with Apple’s Identify your Apple Watch list.
The A-number identifies the hardware model, including generation, case size, connectivity and regional version. Apple’s lookup page expects this number—not the M-number or serial number.
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- A FULL-FEATURED HEALTH TRACKER—Apple Watch Series 11 gives you invaluable insights about your body, right from your wrist. Take an ECG anytime* and get alerts for a high and low heart rate or an irregular rhythm*—so you can stay closer to your heart. You can also view your overnight health tracking metrics with the Vitals app* and be notified of possible sleep apnea.*
- KNOW YOUR SLEEP SCORE—With advanced sleep tracking, Series 11 gives you a daily sleep score. It’s an easy way to help measure and understand the quality of your sleep, so you can make it more restorative.
- GET HYPERTENSION NOTIFICATIONS—Did you know that Series 11 can spot signs of chronic high blood pressure? By analyzing how your blood vessels respond to beats of the heart, it can notify you of possible hypertension.*
- SAFETY FEATURES—A smartwatch that puts your safety first. Series 11 can detect a hard fall or severe car crash, automatically help connect you with emergency services, and notify your emergency contacts.* Check In can automatically notify a loved one when you’ve arrived at your destination.
- A POWERFUL FITNESS TRACKER—With advanced metrics and motivating features like Pacer, Heart Rate Zones, training load, and Workout Buddy powered by Apple Intelligence from your nearby iPhone*—Series 11 is made to help everyone stay active, from runners and hikers to strength-training enthusiasts.
Find the model number on the Apple Watch itself
If you have the watch but not the paired iPhone, use its Settings app:
- Open Settings on the Apple Watch.
- Tap General > About.
- Look for Model Name and Model Number.
Model Name may identify the generation directly. The A-number is the more reliable reference for distinguishing case size, GPS from GPS + Cellular, or a regional variant.
The same screen also shows the serial number and, on cellular models, the IMEI. These are useful for support and ownership records, but they are not the number used in Apple’s model-generation lookup.
Current Apple Watch A-number reference
These examples are from Apple’s identification list. Regional variants can have different A-numbers even when the generation and case size are otherwise the same.
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- A FULL-FEATURED HEALTH TRACKER—Apple Watch Series 11 gives you invaluable insights about your body, right from your wrist. Take an ECG anytime* and get alerts for a high and low heart rate or an irregular rhythm*—so you can stay closer to your heart. You can also view your overnight health tracking metrics with the Vitals app* and be notified of possible sleep apnea.*
- KNOW YOUR SLEEP SCORE—With advanced sleep tracking, Series 11 gives you a daily sleep score. It’s an easy way to help measure and understand the quality of your sleep, so you can make it more restorative.
- GET HYPERTENSION NOTIFICATIONS—Did you know that Series 11 can spot signs of chronic high blood pressure? By analyzing how your blood vessels respond to beats of the heart, it can notify you of possible hypertension.*
- SAFETY FEATURES—A smartwatch that puts your safety first. Series 11 can detect a hard fall or severe car crash, automatically help connect you with emergency services, and notify your emergency contacts.* Check In can automatically notify a loved one when you’ve arrived at your destination.
- A POWERFUL FITNESS TRACKER—With advanced metrics and motivating features like Pacer, Heart Rate Zones, training load, and Workout Buddy powered by Apple Intelligence from your nearby iPhone*—Series 11 is made to help everyone stay active, from runners and hikers to strength-training enthusiasts.
| Apple Watch | Size | GPS | GPS + Cellular |
|---|---|---|---|
| Series 11 | 42mm | A3331 (North America/Europe/Asia Pacific); A3450 (China mainland) | A3335; A3452 (China mainland) |
| Series 11 | 46mm | A3333; A3451 (China mainland) | A3337; A3453 (China mainland) |
| SE 3 | 40mm | A3324; A3391 (China mainland) | A3326; A3327 (China mainland) |
| SE 3 | 44mm | A3325; A3392 (China mainland) | A3328; A3329 (China mainland) |
| Ultra 3 | 49mm | A3281 (North America/Europe/Asia Pacific); A3282 (China mainland) | |
| Series 10 | 42mm | A2997; A2998 (China mainland/Indonesia) | A3001; A3002 (China mainland) |
| Series 10 | 46mm | A2999; A3000 (China mainland/Indonesia) | A3003; A3206 (China mainland) |
| Ultra 2 | 49mm | A2986 (North America/Europe/Asia Pacific); A2987 (China mainland) | |
Apple’s official page includes earlier generations too. Use the exact A-number rather than trying to identify a watch from its appearance. Special editions and different materials can share the same A-number as the corresponding standard hardware.
What the different numbers mean
| Number | What it identifies | Where to use it |
|---|---|---|
| Model number | Five-digit hardware identifier beginning with A | Apple’s model lookup page |
| Part number | Configuration or sales part, beginning with M | Product and sales details; tap it to reveal the A-number |
| Serial number | The individual physical watch | Apple support and ownership records |
| IMEI | Cellular hardware identifier | Cellular support and network-related checks |
Both the iPhone’s Apple Watch > My Watch > General > About screen and the watch’s Settings > General > About screen can show these details. An IMEI appears only on GPS + Cellular models.
Can you identify an Apple Watch from its case size?
Not exactly. Case size narrows the possibilities but does not identify the generation on its own:
- 40mm appears on Apple Watch SE, SE 2, Series 4, Series 5 and Series 6.
- 41mm appears on Series 7, Series 8 and Series 9.
- 42mm appears on multiple generations, including Series 10 and Series 11.
- 44mm appears on SE, SE 2, Series 4, Series 5 and Series 6.
- 45mm appears on Series 7, Series 8 and Series 9.
- 49mm identifies an Ultra-family case, but not whether it is an Ultra, Ultra 2 or Ultra 3.
Read the size alongside the A-number. A band, case or screen protector can make visual size comparisons misleading.
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- GET SMARTER HEALTH INSIGHTS—Apple Watch SE 3 is an advanced health tracker that helps you better understand your body. The smartwatch sends alerts for an irregular heart rhythm, or an unusually high or low heart rate.* You can view your overnight health tracking metrics with the Vitals app,* track your sleep score, and get sleep apnea notifications.*
- A GREAT FITNESS TRACKER—SE 3 can track your workouts in a healthy number of ways—from running and strength training to simply achieving your 10K steps a day. With real-time metrics and Workout Buddy powered by Apple Intelligence from your nearby iPhone,* you’ll hit your goals like never before.
- KEEP HELP CLOSE AT HAND—SE 3 is a smartwatch that can detect a hard fall or severe car crash and automatically help connect you to emergency services and notify your emergency contacts.* Check In can automatically notify a loved one when you’ve arrived at your destination.
- WOMEN’S HEALTH INSIGHTS—SE 3 has advanced sensors that track your wrist temperature while you sleep. With this smartwatch, you can log your periods and symptoms, get period predictions, and get notified of cycle deviations.*
- GREAT BATTERY LIFE AND FASTER CHARGING—Enjoy a smartwatch with all-day, 18-hour battery life* from sunup to sundown. Then charge up to twice as fast as SE 2* and get up to 8 hours of battery in just 15 minutes.*
How to tell if it is GPS or GPS + Cellular
The A-number and About screen are dependable ways to confirm connectivity. Physical details can provide clues, but they are not universal:
- Many older cellular models have a red ring or red cap on the Digital Crown.
- Some newer aluminum cellular models use a ring that matches the case color.
- Apple Watch Ultra models use an orange ring on the Digital Crown.
A red Crown ring does not identify one particular generation, and its absence does not prove that a watch is GPS-only. Confirm the model number instead.
Reading the engraving on the case
For Apple Watch Series 1 and later—including SE, Nike, Hermès and Ultra models—remove the band and inspect the inside of the band slot for the serial number. On the first-generation Apple Watch, the serial number is engraved on the back.
The back engraving may also give clues about case size or materials, but it is not a substitute for the A-number. If the watch will power on, the on-device About screen is more useful. If it will not turn on, use the paired iPhone’s Apple Watch app.
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- GET SMARTER HEALTH INSIGHTS—Apple Watch SE 3 is an advanced health tracker that helps you better understand your body. The smartwatch sends alerts for an irregular heart rhythm, or an unusually high or low heart rate.* You can view your overnight health tracking metrics with the Vitals app,* track your sleep score, and get sleep apnea notifications.*
- A GREAT FITNESS TRACKER—SE 3 can track your workouts in a healthy number of ways—from running and strength training to simply achieving your 10K steps a day. With real-time metrics and Workout Buddy powered by Apple Intelligence from your nearby iPhone,* you’ll hit your goals like never before.
- KEEP HELP CLOSE AT HAND—SE 3 is a smartwatch that can detect a hard fall or severe car crash and automatically help connect you to emergency services and notify your emergency contacts.* Check In can automatically notify a loved one when you’ve arrived at your destination.
- WOMEN’S HEALTH INSIGHTS—SE 3 has advanced sensors that track your wrist temperature while you sleep. With this smartwatch, you can log your periods and symptoms, get period predictions, and get notified of cycle deviations.*
- GREAT BATTERY LIFE AND FASTER CHARGING—Enjoy a smartwatch with all-day, 18-hour battery life* from sunup to sundown. Then charge up to twice as fast as SE 2* and get up to 8 hours of battery in just 15 minutes.*
If the Apple Watch is lost, dead or unavailable
When the watch itself cannot be inspected, open the paired iPhone’s Apple Watch app and go to My Watch > General > About. The app can display model information and the serial number associated with the watch.
If you only have a serial number, it can help Apple Support locate device records, but it cannot be entered directly into Apple’s model-number list. Find the A-number to identify the exact generation.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Regional and special-edition details
Apple sometimes assigns different A-numbers to the same generation and size depending on the sales region. China mainland variants are common in Apple’s tables, and cellular configurations can have additional regional differences.
Hermès, Nike and Edition watches may share an A-number with corresponding standard hardware. The number can identify the underlying generation without uniquely identifying the finish, band or collection.
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- A FULL-FEATURED HEALTH TRACKER—Apple Watch Series 11 gives you invaluable insights about your body, right from your wrist. Take an ECG anytime* and get alerts for a high and low heart rate or an irregular rhythm*—so you can stay closer to your heart. You can also view your overnight health tracking metrics with the Vitals app* and be notified of possible sleep apnea.*
- KNOW YOUR SLEEP SCORE—With advanced sleep tracking, Series 11 gives you a daily sleep score. It’s an easy way to help measure and understand the quality of your sleep, so you can make it more restorative.
- GET HYPERTENSION NOTIFICATIONS—Did you know that Series 11 can spot signs of chronic high blood pressure? By analyzing how your blood vessels respond to beats of the heart, it can notify you of possible hypertension.*
- SAFETY FEATURES—A smartwatch that puts your safety first. Series 11 can detect a hard fall or severe car crash, automatically help connect you with emergency services, and notify your emergency contacts.* Check In can automatically notify a loved one when you’ve arrived at your destination.
- A POWERFUL FITNESS TRACKER—With advanced metrics and motivating features like Pacer, Heart Rate Zones, training load, and Workout Buddy powered by Apple Intelligence from your nearby iPhone*—Series 11 is made to help everyone stay active, from runners and hikers to strength-training enthusiasts.
For Apple Watch models bought in the United States on or after January 18, 2024, a part number ending in LW/A indicates that Blood Oxygen data analysis is performed on the iPhone, with results viewed in the Health app. Apple says this requires the latest iOS and watchOS versions.
Common identification mistakes
- Searching for the M-number: tap the Model Number field to switch it to the A-number.
- Using the serial number: the serial identifies your individual watch, not the generation in Apple’s model table.
- Relying on case size: several generations share the same sizes.
- Treating the Crown ring as definitive: ring colors vary by generation, material and connectivity.
- Assuming an edition is a separate generation: Nike, Hermès and Edition models can share the same hardware A-number as standard versions.
- Trusting the watch face or band: both are replaceable and can make different generations look alike.
For a final check, copy the A-number exactly and compare it with Apple’s official identification page.
FAQ
Where do I find my Apple Watch model number?
On an iPhone, open the Apple Watch app and go to My Watch > General > About. On the watch, open Settings > General > About. Tap the number beginning with M once to reveal the five-digit A-number.
Is the Apple Watch serial number the same as the model number?
No. The serial number identifies your individual watch. The model number is the five-digit code beginning with A, such as A2986, and is the number Apple uses to identify the hardware model.
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Can I identify an Apple Watch from its case size?
Only partially. Several generations share the same case sizes, and all Ultra generations use 49mm cases. Use the case size together with the A-number for accurate identification.
How can I tell whether my Apple Watch has cellular?
Check the A-number or the About screen. A red or matching-color Crown ring can be a clue on some models, while Ultra models commonly have an orange ring, but appearance alone is not conclusive.
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