If you’re sitting there wondering exactly when did apple watch series 4 come out, you probably remember a time when smartwatches were just... okay. They were kinda clunky. They felt like tiny iPhones strapped to your wrist that didn't quite know what they wanted to be.
Then came September 2018.
Apple took the stage at the Steve Jobs Theater and basically reset the clock on what a wearable could do. They didn't just iterate; they overhauled. Honestly, if you look at the Apple Watch lineup today, the DNA of the modern version really started right here with the Series 4.
The Big Reveal: September 12, 2018
The official announcement happened on September 12, 2018.
Apple's Chief Operating Officer, Jeff Williams, stood under those bright lights and introduced a watch that looked significantly different from the "Series 0" through Series 3 models we’d grown used to. It wasn't just a spec bump. It was a redesign from the ground up.
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If you were one of the people refreshing your browser to get an order in, you probably remember that pre-orders opened on Friday, September 14, 2018.
The actual release date—when it hit store shelves—was September 21, 2018.
It launched alongside the iPhone XS and iPhone XS Max. It was a massive day for Apple fans, but surprisingly, the watch stole a lot of the phone's thunder. Why? Because for the first time, the watch felt like it could actually save your life, not just count your steps.
What Made the Series 4 a Massive Deal?
Before the Series 4, Apple Watches had these thick, chunky black borders around the screen. They were fine, but they felt small.
The Series 4 changed the game by pushing the display nearly to the edge. We’re talking about a 30% larger display area. Apple moved away from the old 38mm and 42mm sizes and introduced the 40mm and 44mm cases we still see variations of today.
But it wasn't just the screen.
The ECG Feature (The "Holy Crap" Moment)
This was the big one. The Series 4 was the first over-the-counter consumer device that allowed users to take an electrocardiogram (ECG) right from their wrist.
Funny story: the FDA actually granted "De Novo" classification for the ECG app and the irregular heart rhythm notification just one day before the announcement. Rumor has it there was some serious sweating happening behind the scenes at Apple Park. If that clearance hadn't come through by September 11, the keynote on the 12th would have looked very different.
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The watch used electrodes built into the Digital Crown and the back crystal. You'd hold your finger on the crown for 30 seconds, and it would tell you if your heart rhythm looked normal or if there were signs of Atrial Fibrillation (AFib).
Fall Detection
Another feature that seemed almost like magic back then was Fall Detection. Using a new accelerometer and gyroscope that could measure up to 32 g-forces, the watch could tell if you took a "hard fall."
If you didn't move for about a minute after the impact, it would automatically call emergency services and send your location to your emergency contacts. At the time, critics wondered if it would just be a series of false alarms. As it turns out, it became one of the most-cited features in "Apple Watch saved my life" stories over the following years.
Under the Hood: The S4 Chip
Inside, the Series 4 packed the S4 silicon.
This was a 64-bit dual-core processor that Apple claimed was up to two times faster than the S3. If you ever used a Series 3, you know that sometimes apps would hang or Siri would take a beat too long to wake up. The Series 4 made everything feel snappy. It felt... "pro."
The speaker got a massive upgrade too. It was 50% louder, specifically designed to make phone calls and Siri responses clearer. They also moved the microphone to the opposite side of the speaker to reduce echo during calls. Small touch, big difference.
Pricing and Availability at Launch
When it dropped in late September 2018, the pricing was a bit of a jump for some.
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- GPS Model: Started at $399
- GPS + Cellular Model: Started at $499
You could get it in the classic Silver, Space Gray, and Gold aluminum finishes. If you wanted to get fancy, the stainless steel models (including that gorgeous Space Black and a new polished Gold) were the premium options.
A Quick Timeline of the Series 4 Era
To put things in perspective, here is how the window of the Series 4's life looked:
- Sept 12, 2018: Announced at the "Gather Round" event.
- Sept 21, 2018: Official store release.
- Dec 6, 2018: The ECG app officially launches in the US via watchOS 5.1.2.
- Sept 10, 2019: Apple officially discontinues the Series 4 to make room for the Series 5 (which added the Always-On display).
It’s actually kinda wild that the Series 4 only had a "shelf life" of one year before being replaced. But that’s the Apple way. Even though it was discontinued quickly, it supported software updates for years, proving how powerful that S4 chip really was.
Does Anyone Still Use a Series 4 in 2026?
Believe it or not, yes.
While we’re well into the era of the Apple Watch Series 11 and Ultra 3, the Series 4 is still kicking for some people. The battery is usually the first thing to go. Most people who still have a Series 4 have likely seen their battery health drop into the 70% range, meaning it barely makes it through a full work day.
However, because it was the first "modern" design, it doesn't look as dated as the Series 3. The Series 3 had that square-within-a-square screen look that screams "2017." The Series 4 still looks sleek.
Comparing the Series 4 to What Came Before
| Feature | Series 3 (2017) | Series 4 (2018) |
|---|---|---|
| Case Sizes | 38mm / 42mm | 40mm / 44mm |
| Display | Standard OLED | LTPO OLED (30% larger) |
| Processor | S3 (32-bit) | S4 (64-bit) |
| Heart Sensor | Optical only | Optical + Electrical (ECG) |
| Fall Detection | No | Yes |
| Bluetooth | 4.2 | 5.0 |
Why This Specific Release Mattered
The Series 4 was the moment the Apple Watch transitioned from a "notification machine" to a "health guardian."
Before 2018, the watch was a luxury. After the Series 4 launched, doctors actually started recommending them to patients with heart concerns. It was the first time a major tech company successfully navigated the bridge between Silicon Valley gadgetry and FDA-regulated medical utility.
It also introduced the Infograph watch face, which—love it or hate it—is still one of the most popular faces because it can hold up to eight complications. It was the first time we could see weather, heart rate, calendar, and activity all without tapping a single button.
Actionable Steps for Older Watch Owners
If you still happen to have an Apple Watch Series 4 tucked in a drawer or on your wrist, here is what you should do:
- Check Battery Health: Go to Settings > Battery > Battery Health. If it's below 80%, the "Peak Performance Capability" is likely throttled. It might be time for a replacement or a trade-in.
- Trade-In Value: In 2026, the trade-in value for a Series 4 is minimal (likely $30-$50 at best), but some retailers offer "recycling" credits toward a new model.
- Update it One Last Time: If you're handing it down to a kid or a relative, make sure it’s running the latest version of watchOS it can handle. It won't support the newest 2026 features, but for basic fitness tracking and heart monitoring, it's still surprisingly capable.
- Check Your Straps: One of the best things Apple did was keep the band compatibility. Your Series 4 bands (40mm or 44mm) will still fit the modern 41mm and 45mm watches perfectly. Don't throw them away if you upgrade!
The Series 4 wasn't just another gadget; it was the blueprint for every Apple Watch that followed. Knowing it came out in September 2018 helps explain why so many people felt comfortable finally jumping into the smartwatch world back then.